1 tablespoon vegetable oil
2 pounds ground beef, 85 percent or leaner
1 1/2 cups onion, chopped
1 cup green bell pepper, chopped
1 clove garlic, minced
2/3 cup water
2 cups ketchup
3 tablespoons brown sugar
1 1/2 tablespoons Worcestershire sauce
1 tablespoon Dijon mustard
8 sandwich buns