Heat olive oil and salt pork in a Dutch oven.

Add leg of lamb, onion, celery, carrots, salt, and pepper to the Dutch oven.

Cook over medium heat, turning the meat frequently, until browned on all sides.

Add garlic and continue cooking until the lamb is well browned.

Pour in dry white wine and cook until the wine has nearly evaporated.

Stir in tomato paste, oregano, and parsley. Cook for about 5 minutes.

Add lamb stock or water, cover the pot, and continue cooking for 1 1/2 hours, turning the meat occasionally.

Once the lamb is cooked through, remove it from the pan and place it on a warm platter to rest.

Strain the gravy from the pan, discarding the solids.

Serve the gravy over the leg of lamb.