What follows are three sauces that are the cornerstones of the Italian and Italian Jewish kitchens. The first is the classic cream sauce known as besciamella, which is better known by its French name, béchamel. It acts as a thickener or liaison in soups, puddings, and gratins, as well as a sauce. Obviously it cannot be used in any dish that has meat, or even in a meal where any meat is served. It provides a note of richness at dairy dinners.
The mayonnaise is pareve; it can be used at both dairy-and meat-based meals. Always made with golden yellow yolks from eggs that are not fertilized, that is, without blood spots, mayonnaise is served with cold cooked fish, tuna or chicken loaf, hard-boiled eggs, and cooked vegetables. It should have enough lemony tartness to cut through the inherent richness of the emulsified yolk-and-oil-based sauce. You may use all pure olive oil or part extra-virgin oil for fruitier taste. Using all extra-virgin olive oil may make the mayonnaise too strong in flavor, however, thus possibly overpowering the dish it is to accompany.