Easy Crock Pot Sloppy Joes

Ingredients :

2 lbs ground beef

1 small onion, finely diced

1 green bell pepper, diced

3 cloves garlic, minced

1 cup ketchup

2 tbsp tomato paste

2 tbsp brown sugar

1 tbsp yellow mustard

1 tbsp Worcestershire sauce

1 tsp salt

1 tsp black pepper

6 hamburger buns