Pan sauce
The brown bits stuck to the skillet after you sear meat are concentrated flavor. Pour off all but a tablespoon of fat, soften a minced shallot in it for one minute, then add half a cup of wine or stock and scrape the bottom with a wooden spoon. Boil the liquid until it has reduced by half, which takes about three minutes. Take the pan off the heat, swirl in two tablespoons of cold butter, and season with salt and a few drops of lemon.
Tomato sauce
Warm three tablespoons of olive oil with three sliced garlic cloves over medium-low heat until the garlic is fragrant but not brown. Add a 28-ounce can of whole tomatoes, crushed in your hand, and half a teaspoon of salt. Simmer for 20 to 25 minutes, stirring now and then, until the sauce thickens and the oil pools at the edges. That is enough for a pound of pasta.
White sauce
Melt two tablespoons of butter over medium heat, whisk in two tablespoons of flour, and cook the paste for a minute to take away the raw taste. Pour in a cup and a half of milk gradually, whisking the whole time, and simmer for five minutes until it coats a spoon. Season it with salt, pepper and a little nutmeg. Stir in a cup of grated cheddar off the heat and you have cheese sauce for macaroni or vegetables. Lumps come from adding the milk too fast.
Green herb sauce
Finely chop a packed cup of parsley, or parsley mixed with cilantro, along with one garlic clove. Stir in half a cup of olive oil, two tablespoons of red wine vinegar, a quarter teaspoon of salt and a pinch of red pepper flakes. It needs no cooking, keeps for three days in the refrigerator, and improves steak, fish, chicken, eggs and roasted vegetables equally.
Stir-fry sauce
Whisk together three tablespoons of soy sauce, two tablespoons of water, one tablespoon of rice vinegar, one tablespoon of honey, a teaspoon of toasted sesame oil and a teaspoon of cornstarch, with grated garlic and ginger if you have them. Pour it over the vegetables and meat in the last minute of cooking. It has to come to a boil, because cornstarch only thickens at that point, and it turns glossy within 30 seconds. This quantity serves two or three.
Tip Taste every sauce on the food it is meant for, not from the spoon. A sauce that seems slightly too salty or sharp by itself is usually right once it meets plain pasta or meat.
