Prepare the aromatics: Peel and wash the onions, carrots, leeks, celery, and turnips. Cut the onions in half and sauté them in a saucepan until browned. Stud one of the browned onion halves with the cloves (stick the pointed ends into the flesh of the onion).
Prepare the meats: Trim the pieces of meat from their bones and trim away any excess fat. Truss the meat as necessary. Place the bones in ice water.
In a large pot, bring 5 quarts (5 L) of cold, salted water to a boil with the bones, bouquet garni, and garlic. As soon as the water begins to boil, add the meat. Remove the bones and the marrow 5 minutes after the water starts to boil. Cook over very low heat for 4₁ ⁄₂ hours. Regularly skim off any foam and impurities that collect on the surface; the broth should be clear and a light golden color.
Prepare the vegetables: Wash and peel the potatoes, carrots, and turnips. Strip away any fibrous threads from the celery stalks and cut the celery and leek whites into large pieces. Remove some of the cooking broth and begin cooking the carrots, turnips, celery, and leeks in the broth 30 minutes before the end of the meat cooking time. Add the potatoes to a pot of cold, salted water and bring to a boil and cook until they are tender.
Add the pieces of meat to a large shallow serving platter. Arrange the vegetables around the meat and drizzle the meat and vegetables with the cooking juices.