Add ground beef to a large skillet over medium heat. Cook until the meat browns and season it with salt and pepper. Drain grease.
Add the onion and minced garlic to the ground beef and cook for 2 minutes.
Stir in the Dijon mustard, ketchup, barbecue sauce, and Worcestershire sauce until well combined.
Reduce the heat and let the mixture simmer for 20 minutes. Season with salt and pepper to taste.
While the sloppy Joe mix is simmering, toast the hamburger buns on a baking sheet under the broiler for 2 minutes or until the buns are golden brown.
Fill the toasted hamburger buns with the sloppy Joe mixture. Serve immediately. Enjoy!