In a large skillet over medium-high heat add the diced onions and ground beef. Season with beef bouillon powder, salt and pepper. Cook until no pink is visible within the meat, add minced garlic and cook for 30-4 seconds then drain off the excess grease.

Add tomato sauce, ketchup, mustard, and brown sugar. Stir until well combined and bring to a simmer over low-medium heat.

In a separate skillet over medium heat, coat one side of each piece of bread with a thin layer of mayo and place that side down in the skillet. Place a slice of cheese on top of the slice of bread and add a serving of the sloppy joe mixture. Then add another piece of cheese on top of the mixture and place a toasted piece of bread on top. Serve & enjoy!