Place onions, garlic, and celery on the bottom of a large greased Pyrex baking dish or Dutch oven. Place meat on top. Sprinkle meat with black pepper; then pour vinegar, olive oil, honey, and cloves onto the meat. With gloved hands, smear the vinegar, olive oil, honey, and cloves evenly all over the meat. Add bay leaves and red wine to the dish. Cover and marinate for two hours or overnight in the refrigerator.

Preheat oven to 300 degrees Fahrenheit. Make sure the meat is very well covered and bake for four to five hours, depending on the size of the meat. Start checking at three and a half hours. (If the meat has a bone, you can increase cooking time to six hours.) Calculate 45 minutes per pound as your cooking time. Let cool.

Refrigerate overnight before slicing.

To finish the gravy, skim off the fat from the meat. Then, remove the bay leaves and any cloves you can easily find, and puree the vegetables with an immersion blender. You can choose to reheat the gravy separately or in the same pan with the meat.