Cut pork into large chunks. Coarsely chop tomatoes. Peel potatoes and cut into thick chunks. Seed, core, and thinly slice bell pepper. Brown pork in 2 tb oil if desired. Layer ingredients in crockpot in order; cook until meat is tender, about 10 hours.
Stovetop preparation: Heat oil in dutch oven over medium heat. Add pork and saute a few minutes, until lightly browned. Add garlic and saute well. Add onion and saute until tender. Add tomatoes and cook 5 minutes. Add water, vinegar, and bay leaf. salt and pepper to taste. Bring to boil. Cover and simmer until pork is almost tender, about 40 minutes. Stir in green pepper. Add potatoes around sides and simmer, covered, until tender, about 15 minutes. Avoid stirring or overcooking potatoes.