Brown the beef. In a large skillet over medium heat, cook the ground beef and chopped white onion together, seasoning with salt and pepper to taste. Stir occasionally until the beef is browned and the onion is tender. Drain excess grease if needed.

Add the remaining ingredients. Stir in the chicken gumbo soup, ketchup, flour, prepared mustard, barbecue spice, and chili powder. Mix until everything is well combined.

Simmer until thickened. Reduce the heat to low and simmer, stirring occasionally, until the mixture thickens to your desired consistency.

Make the sandwiches. Spoon the warm Sloppy Joe mixture onto hamburger buns.

Serve and enjoy! Serve with Ruffles or your favorite wavy potato chips for a classic, satisfying family meal.