Brown the ground beef in a large pot over medium-high heat. Drain off the fat.
Add the red onion and garlic. Cook until onion is translucent.
Add the water, tomato sauce, brown sugar, chipotle pepper, Worcestershire. Stir to combine, cover and simmer over medium-low heat for 15 minutes. Take lid off an simmer for 3 more minutes and sauce thickens.
Crisp flatbreads in oven on baking sheet for 4 minutes. Remove flatbreads from oven and divide Sloppy Joe meat mixture over flatbreads, top with cheddar cheese and bake in 350°F oven for 3 minutes until warm and cheese has melted.
Garnish with reserved diced red onion, cut and serve.