Ham and Parsley Terrine

Ingredients

• 2 small onions, peeled and studded with 3 cloves each
• 3⁄4 cup finely chopped flat-leaf parsley leaves, stems reserved
• 10 black peppercorns
• 4 unsmoked ham hocks (about 4 lbs.)
• 3 carrots, halved crosswise
• 2 ribs celery, halved crosswise
• 2 bay leaves
• 2 fresh thyme sprigs
• 1 (750-ml) bottle dry white wine
• 1 oz. gelatin
• Kosher salt, to taste
• 1 3⁄4 lb. unsmoked cooked ham, cut into 3⁄4" cubes
• 2 shallots, finely chopped
• 1 clove garlic, finely chopped