Finely chop the onion. Seed and finely dice the green pepper.
In a bowl, combine the Worcestershire sauce, mustard, brown sugar, and tomato sauce.
Place a large skillet over medium/high heat. Add olive oil and ground beef. Saute the beef for about 5 minutes until cooked through and no longer pink, breaking it up with a spatula. Season with salt and pepper.
Add in the green bell pepper and onion. Cook another 5 minutes until the veggies are tender and meat is browned.
Add the minced garlic and sauté 30 seconds until fragrant, stirring constantly.
Add in the combined sauces mixture and bring to a light boil. Add the garlic and onion powder and mix in. Reduce heat to low and simmer uncovered for about 10-15 minutes or until thickened to your liking. Season to taste with salt and pepper and add water if you prefer a looser consistency.
Serve on toasted buns!