Preheat oven to 350 degrees.
In a skillet, brown your ground chuck. Add the onion to cook with it, if using. If you are using minced garlic, add it right before you add the sloppy joe mix to avoid bitterness.
Once the meat is browned, drain the excess grease. Stir in the can of sloppy joe mix & cook on medium/low for about 5 minutes, or until slightly thickened. Evenly spread half the sloppy joe/beef mixture each french bread half. Combine the two shredded cheeses & sprinkle on top.
Bake at 350 for 10 minutes.