1 small onion, finely chopped
1/2 small green bell pepper, seeded and finely diced
1 Tbsp worcestershire sauce
1 1/2 tsp yellow mustard
1 Tbsp brown sugar
15 oz can tomato sauce
1 lb lean ground beef, 85%-90% lean
1 Tbsp olive oil
1/2 tsp salt, or to taste
1/4 tsp ground black pepper, or to taste
3 garlic cloves, minced
1/4 cup water, optional, or added to desired consistency
4 hamburger buns, toasted if desired