In a large bowl, mix all of the meatball ingredients together until well combined. Preheat the broiler and form golf ball sized meatballs. Spread the meatballs out on a baking sheet and broil for about 5 minutes per side to brown. Remove from heat.
Slice the plantains into 1 inch slices. Preheat some vegetable oil in a pan and shallow fry the plantains for about 3 minutes per side until golden brown and soft.
Build the sandwich first with the bread, then the cheese, then bbq sauce, then meatballs sliced in half, then plantains, more bbq sauce, and more cheese. Put the top bread on.
Cook the sandwich in a pan with some butter, pressing it so it is very thin and gets a nice crunch on the top and bottom. Once the cheese is melted, remove from heat, slice, and serve.