Dolly Parton's Cowboy Beans

1 pound ground beef
2 medium onions, chopped fine
1 small bell pepper, chopped fine
2 (16 ounce) cans pork and beans
2 cups catsup
1 teaspoon vinegar
1/4 cup brown sugar, firmly packed
2 teaspoons prepared mustard
1 teaspoon salt
1 teaspoon pepper

Preheat oven to 350 degrees F.

Brown ground beef, onions, and pepper in a 10-inch skillet. Add remaining ingredients. Pour into baking dish and bake for about 15 to 20 minutes or until mixture is bubbly.