Mix a dry cure with the coarse salt, sugar, and saltpeter. Weigh the ham, then put it onto a wooden worktable or countertop. Rub it well with the salt cure, packing the cure around the bone at either end. Place the ham in a wooden box and store it in a cool place (between 36°F and 40°F) for 2 days for each pound of ham. Check the ham every 7 days. If the salt has melted and run off, resalt the ham.
At the end of the curing time, remove the ham. Rinse it under running cold water, then rinse it with wine. Tie a cord to the shank end and hang the ham in a cool place for 2 days.
After 2 days, mash some garlic into a paste and rub the exposed meat of the ham. Dice the pork fat, put it into a skillet, and fry until fat is rendered. (save the residue for crackling bread, or eat the bits on the spot.) Make a paste of the pork fat, flour, salt, pepper, and about 3 tablespoons water. Cover the ham with this paste. Wrap a sheet of cheesecloth around the ham, then place it in a large brown paper bag. Tie the paper bag loosely and hang the ham in a cool, airy place for at least 3 months.