Slow Cooker Sloppy Joes

3 pounds ground beef
2 tablespoons shortening
1 cup onion, chopped
1 cup diced celery
1 green pepper, chopped
1 garlic clove, minced
2 tablespoons Worcestershire sauce
1 cup catsup
3 beef bouillon cubes, crushed
1/2 teaspoon paprika
1/4 teaspoon pepper
6 ounces tomato paste
1 1/4 cups water
3 tablespoons vinegar
3 teaspoons brown sugar
1 teaspoon dry mustard

1. Heat shortening in skillet and brown meat, discard fat.
2. Add remaining ingredients stir well.
3. Cover and cook on low 6-8 hours; or high 3-4 hours.
4. Serve over your favorite warmed buns.
5. Enjoy