Kidney beans pick up flavors well, making them ideal for marinating or adding to stews. When cooking them with tomatoes or tomato sauce, it is usually better to precook the beans, as otherwise the acids in the tomato may prevent the beans from softening and so require longer cooking time. Soak the dried beans for 12 hours before cooking, then pressure-cook for 20 minutes, or simmer on the stove for 1 1/2 to 2 hours. 1 cup of dried beans makes approximately 3 cups of cooked beans. Use kidney beans to make chili, and add them to stews, soups, and salads, as well as to grain and vegetable dishes.