Before cooking brains, blanch them briefly to firm them, or soak in several changes of cold, acidulated water, made by adding a small amount of vinegar or lemon juice to water. Sweetbreads should be soaked in several changes of acidulated water for best flavor.
Remove membranes or excess fat from the exterior of specialty meats. Split kidneys and remove fatty tissue and veins. Scrub tongue. To disjoint oxtail, cut into sections with a sharp knife; avoid cutting the bones.
Slice sweetbreads, brains, heart, or liver and dredge in flour and spices if desired. Heat butter or oil in a skillet. Saute over medium heat until brown on each side and done in the middle.
Heat cooking liquid with herbs, spices, and vegetables in a Dutch oven. Add brains, heart, kidneys, tripe, tongue, oxtail, or pig's feet (it is best to use just one type of meat at a time). Cover and cook in the oven at 325F (160C), or simmer on the stovetop from 45 minutes to three hours, depending on variety meat used.
Bring court bouillon (broth or wine with vegetables or herbs) or cooking liquid to a simmer. Add brains or sweetbreads and simmer over low heat for 20 minutes. Drain and serve.
Arrange split kidneys on skewers and brush with oil and seasonings. Place on a broiling pan 3 inches (7.6cm) from the heat source. Broil until brown on the outside but still tender on the inside, approximately 5 minutes on each side
Place liver in a dish and cook on High for 7 to 8 minutes per pound. Place heart in a dish, add broth, cover, and cook on High 45 to 50 minutes per pound (454g). Place kidneys in a shallow baking dish and cook on High 11 to 12 minutes per pound (454g). Place oxtail in a shallow baking dish, cook on high for 5 minutes, turn, and cook another 6 to 8 minutes. Add water, cover, and cook 6 to 8 minutes. Put tongue in a casserole with cooking liquid and cook on Medium until tender, about 70 minutes for 2 1/2 pounds (1.125 kg). Place brains in a casserole and cover with broth. Cook 6 to 8 minutes on High, then 10 to 12 minutes on Medium. Drain, dredge with bread crumbs, and cook another 5 minutes on High. Cover sweetbreads with cold water and cook on High until boiling. Drain, add broth and butter, cover, and cook another 3 to 5 minutes on Medium.