Wok hei, means ‘the breath of the wok,’ it is the smoky flavours, aroma and texture the dish picks up whilst being stir-fried in a hot wok. It is particularly prevalent in Cantonese cooking. To impart wok hei the traditional way, the food is cooked in a seasoned traditional cast iron wok over a very high flame while being stirred and tossed quickly. The heat needs to be extremely high to stop the food being boiling in its own juices and being stewed. When you see professional Chinese chefs cooking over gas stoves or an open flame, they toss the food at an angle allowing for the splattering of fine oil particles to catch the flame into the wok adding more Wok hei.
Thickening sauces have developed from using starchy vegetables, the ground nuts, and breadcrumbs from medieval cookery to using gums and gelling agents in today’s advanced gastronomy. The most common and popular methods are;
A roux is a mixture of flour and fat used to thicken sauces, soups, and stews. It is traditionally used to thicken the classical French Béchamel, Velouté, and Espagnole sauces and in Cajun and Creole cooking. The roux is made from equal parts wheat flour and either butter, vegetable oil, bacon drippings or lard which are cooked together with or without colouring. The warm liquid such as stock or scalded milk is then slowly whisked in to the cooked roux, which is then cooked out over a low heat.
This is a French term meaning to finish a sauce with butter forming an emulsion. Immediately before serving you can whisk in chunks of cold unsalted butter, one at a time, into a hot sauce. The sauce must not boil or the butter emulsion will split. The finished sauce has a velvety texture and rich flavour.
Is a paste made by kneading butter and flour together which can be crumbled over and quickly whisked into a simmering sauce. It can be made in advance and stored in the refrigerator. A ratio of fifty grammes of butter to seventy-five grammes of plain flour will thicken one litre of sauce.
This is a mixture of cream and egg yolks, used to thicken soups and sauces. Never add directly to hot liquids or the eggs will cook out and scramble. Temper the liaison by adding a small amount of the hot sauce to it which gradually raises the temperature, then whisk this mixture back into the remaining sauce. DO NOT BOIL and serve straight away. This is a very rich method of finishing classic sauces.
This is the same as the American term “cooking down” … as the stock or sauce simmers water vapour evaporates. This thickens the sauce and intensifies the flavour. Use a large heavy pot and bring the liquid or sauce to a gentle simmer, a vigorous boiling may burn the sauce and evaporate volatile flavourings. Many of the sauces found in modern cuisine are based on reductions see Demi-glace.
A slurry is a mixture of a starch and cold water. You can use cornstarch for thickening milk or dairy sauces, arrowroot used to thicken fruits juices because of the clear, glossy finished result on fruit tarts, potato starch, rice flour, wheat flour or dried powdered yam. The ration is one-part starch with two parts cold water. Always remove the sauce from the heat before adding the slurry to stop the starch cooking in thin streams or ribbons and not mixing. Then return to the heat stirring continuously.
Tomato concassé is the flesh from fresh tomatoes that have been peeled, de-seeded and chopped into a dice. It is a staple of many professional kitchens used in sauces, omelettes, with olive oil, garlic, and basil as a topping for bruschetta and when added to Béarnaise sauce to make Choron sauce, served with fish and seafood. We remove tomato seeds and skin from Tomato concassé as in large quantities they can be tough, do not soften during cooking and leave a bitter flavour. If you can get hold of a moderate amount of ice it is very useful when cooling off the blanched tomatoes. Use fully ripe but firm tomatoes for the best results. The process may seem to be quite an effort but the end results for Tomato concassé are very pleasing and worthwhile.
To make tomato concassé
Turn the tomato over and on the other end mark a small cross in the skin with the knife.
When all your tomatoes are prepared, place a four or five at a time into the pan the boiling water. As soon as the water returns to a boil cook for one-minute longer and then remove them using a slotted spoon or spider.
Immediately plunge the blanched tomatoes into a large bowl of very cold water to arrest the cooking process. If you have ice, use iced water. The cooking process depends on the size of tomatoes you are using, small tomatoes may only require thirty seconds simmering. A good rule of thumb is if you see the tomato skin beginning to peel off then take out and cool.
The next step will take a little practice. Drain the blanched tomatoes then using the sharp knife again gentle tease and peel off the skin. Start by slowly sliding the tip of the knife under the cross you made in the skin earlier and work down. When peeled quarter the tomatoes and remove the seed with a small spoon or the back of the knife. Chop the quartered tomatoes into large or small dice as required.
A roux is a mixture of flour and fat used to thicken sauces, soups, and stews. It is traditionally used to thicken the classical French Béchamel, Velouté, and Espagnole sauces and in Cajun and Creole cooking. The roux is made from equal parts wheat flour and either butter, vegetable oil, bacon drippings or lard which are cooked together with or without colouring. In Cajun cuisine, the roux is almost always made with oil or lard instead of butter, which would burn and is dark brown in colour, adding greatly to the flavour of the finished sauce. In regional American cuisine, bacon is sometimes rendered to produce the fat to use in a roux for extra flavour, in recipes such a sausage gravy. In the case of meat gravies, fat rendered from meat is often used to make a pan gravy.
Cooking the roux produces the correct chemical structure to thicken the sauce and starts to remove the floury taste from the finished sauce. A light roux of flour and butter, cooked for two or three minutes without colouring is used in the traditional béchamel sauce. Cooking until the mixture becomes golden in colour and sandy in texture produces a blonde roux the base of velouté sauces. Darker roux can range from light brown to chocolate in colour and add a distinct nutty flavour to a dish. The darker the roux, the less thickening power it has, a chocolate roux has about a quarter of the thickening power, by weight, of a white roux.
The golden rules when thickening a roux based sauce is to allow the roux to cool slightly after cooking and use a liquid that is just off the boil to make combining the ingredients much easier. The sauce will then need to very gently simmer for at least thirty minutes to cook out and eliminate any floury taste. The resulting sauce will be smooth, rich and creamy in texture.
Classic Espagnole or Brown sauce is a dark, flour-based sauce with a strong taste and is now replaced in many recipes by a well-reduced beef or roast veal bone stock, traditionally it was a Master Sauce serving as the starting point for many derivative sauces, of which there are hundreds in the French repertoire. As Espagnole is the French word for Spanish it was long thought that the sauce was a creation of a chef to one of the two countries royal courts following a diplomatic marriage between the French and Spanish thrones, similarly, Espagnole was a rich marriage of Spanish tomatoes to a traditional French brown meat sauce. However, according to Alan Davidson, in The Oxford Companion to Food, “The name has nothing to do with Spain, any more than the counterpart term allemande has anything to do with Germany. It is generally believed that the terms were chosen because in French eyes Germans are blond and Spaniards are brown.”
Espangole is made from a dark roux, a Mirepoix of root vegetables and tomatoes, veal or beef stock and aromatics. The sauce is very gently simmered over a low heat and skimmed regularly. Espangole was one of the five mother sauces of the French cuisine of Escoffier and was traditionally used to make Demi-glace which is used in turn to make hundreds of secondary sauces. In the modern kitchen, these sauces are made using a reduced stock and a list can be found under the Demi-glace entry.
A Classic Espangole Recipe
As Espangole was a staple of the large classical kitchen the ingredient list includes parsley stems and mushroom trimmings left over from the preparation of garnishes, these are optional or simply replace with a couple of sprigs of parsley and a few mushrooms.
50 gr Butter or Lard
50 gr Fat Bacon
100 gr Plain Flour
2 large Carrots, peeled and sliced
1 large Onion, peeled and chopped
2 sticks of Celery, washed and chopped
3 cloves of Garlic, peeled and crushed
1 Pigs Trotter
500 gr Shin of beef, with the bone
1 generous sprig of fresh Thyme
1 sprig Rosemary
A small handful of Parsley stems
A small handful of mushroom peelings and stems
6 Black Peppercorns
1 1/2 ltrs of Beef or roasted Veal Stock
440 gr tin chopped Tomatoes
150 ml quality Red Wine
Roast the trotter and beef shin in a very hot oven for twenty minutes until brown. In a very large, heavy bottomed pan melt the butter and fry the bacon, add the mirepoix of root vegetables and cook slowly. Brown the vegetables so the natural sugars caramelise to add flavour and colour to the sauce. Add the flour and cook for at least another five minutes to develop the colour.
Slowly add a quarter of the stock stirring all the time then add the remaining stock, trotter, beef shin and the rest of the ingredients. Bring up to the gentlest of simmers and cook for at least three hours. Skim regularly to remove any impurities and excess fat from the sauce which if let to boil into the sauce will result in a cloudy finish. Remove from heat, allow to cool and pass through a chinois or fine sieve.
In the kitchen, an emulsion is normally the combination of fat and water (or water-based) ingredients. We first encounter natural emulsions when we drink milk and then use cream. We make emulsions when we create a Hollandaise or mayonnaise sauce or a vinaigrette to dress a salad. The result of emulsifying is twofold, dispersing a strong flavour in a usually blander medium, think of the taste of shallot, tarragon and white wine vinegar in the classic Béarnaise and the resulting mouthfeel, the smooth, glossy experience of eating mayonnaise.
So how do cooks combine fat and water even though they don’t like to mix? By using shearing power, that is shaking, stirring, whisking and blending. The physical action disperses one ingredient throughout the other. Emulsions are unstable by nature, your fresh hollandaise splits and your vinaigrette separates but this can be prevented by using emulsifiers and stabilizers. Egg yolks, mustard, and garlic all act as emulsifiers which chemically bind fat and water molecules together. In commercial food production and molecular gastronomy gums, starches and plant particles all act as emulsifiers.
100 ml Virgin Olive Oil
100 ml Sunflower Oil
2 free-range Egg Yolks*
2 tablespoons good White Wine Vinegar
1 tablespoon freshly squeezed Lemon juice
½ teaspoon fine Salt
½ teaspoon English Mustard powder
A pinch of Caster Sugar
Place a glass bowl on a damp cloth to prevent slipping. Whisk together egg yolk and the dry ingredients. Combine lemon juice and vinegar in a small jug then thoroughly whisk half into the yolk mixture. Whisking briskly add the oil a few drops at a time until the liquid starts to thicken (you have formed an emulsion). Increase the flow of oil to a constant, thin stream. Once half of the oil is in add the rest of the lemon juice mixture. Continue whisking until all of the oil is incorporated. Store in the refrigerator.
If your mayonnaise separates or curdles you can recover the mix by whisking in a tablespoon of boiling water to the mayonnaise which should combine the mixture together. If this does not recombine the mixture start the process again with a further egg yolk in a clean bowl and whisk in the curdled mixture a tablespoon at a time.
*There is a slight risk of salmonella and other food-borne illnesses from using raw unpasteurised egg, use only unbroken fresh eggs and do not consume if pregnant or feed to infants.
3 free-range Egg yolks
200 gr Unsalted Butter
2 teaspoons fresh Lemon juice
2 teaspoons warm Water
A pinch Cayenne Pepper
Place the butter in a small pan and set on the back of your stove or hob. The pan does not need to be heated directly just placed somewhere warm enough to melt the butter. Allow the milk solids to sink to the bottom of the pan and decant off the clarified butter. Set aside and keep warm. Place a medium glass or stainless steel bowl over a pan of gently simmering water, being careful not to let the bowl touch the water. In the bowl whisk the egg yolks until they are pale yellow and the resulting mixture has a thick creamy texture. Switch off the heat.
Using a small ladle pour in a thin stream of the warm butterfat while continuously whisking. Continue until all the liquid is incorporated. If the resulting sauce becomes too thick, thin with a little warm water. Add the lemon juice, season to taste and serve. The Hollandaise will keep warm set above the warm water covered lightly with tin foil for fifteen to twenty minutes.
If your Hollandaise splits or curdles you have probably tried to add the butter too quickly, a couple of teaspoons of freshly boiled water whisked vigorously into the split sauce may help retrieve it. If this does not work, you can whisk up a further egg yolk in a fresh clean bowl then slowly add the split hollandaise whisking all the time.