Sloppy Joes

1 onion, chopped
1 green bell pepper, chopped
2 lbs hamburger
4 cups tomato sauce
1/4 cup tomato paste
2 TBSP mustard
2 tsp chili powder
1 tsp salt
1 tsp sugar
1 tsp oregano
1/4 tsp pepper

Cook together onion, bell pepper, and hamburger over medium heat. Stir in the rest of the ingredients and reduce heat to medium-low. Cover and simmer for 15 minutes, stirring occasionally. Serve over roll/bun halves or toast.