To cook the lamb in the Instant Pot:
Combine whatever pieces or cuts of lamb you are using to yield about 1½ pounds cooked meat and place in the Instant Pot. Add 2-3 tablespoons Bourbon or Whiskey (optional) for flavor, then cover the meat with stock (I used pork stock for flavor). Cover and cook on pressure cooker high setting for 45 minutes, then natural release for 15 minutes. Let the steam out, let meat cool slightly, then cut into small chunks, discarding fat, bones, or gristle. Reserve 1 cup of the stock to make the filling.