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 a little water and the ground beef. Saute the beef until cooked through and no longer pink. Season with salt and pepper and add in the diced peppers and onion. Cook another 5 minutes until the veggies are tender and beef is browned.
Add the minced garlic and saute 30 seconds until fragrant, stirring constantly. Add in the sauce and bring to a light boil. 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 for Sloppy Joe Sandwiches.