In a large skillet or pan, add the olive oil, ground beef, and onions, and sauté for 10-15 minutes over medium heat until the ground meat browns. Add the garlic and bell pepper and sauté for 2-3 minutes more until the pepper begins to soften.

Add the tomato sauce, gluten free Worcestershire sauce, and the remaining ingredients (brown sugar, onion powder, garlic powder, and black pepper) to the pan, and cover. Sauté on low heat for 15 minutes until peppers are soft.

Add the cooked meat to the tomato mixture and stir well to combine. Cook for 5 minutes to heat meat all the way through. Taste, and add salt and pepper if needed.

Toast gluten free buns, and add a generous scoop of sloppy joe mixture to the buns. Top with fresh chopped onion and enjoy!

Store leftover filling in an airtight container, refrigerate, and enjoy with in 3 days.