– 1 lb ground beef – 1 onion, finely chopped – 1 bell pepper, finely chopped – 2 cloves garlic, minced – 1/2 cup ketchup – 1/4 cup tomato paste – 1/4 cup brown sugar, packed – 2 tablespoons Worcestershire sauce – 1 tablespoon Dijon mustard – 1 teaspoon chili powder – 1/2 teaspoon smoked paprika – Salt and pepper to taste – 4 hamburger buns