Prepare the garlic toast according to the package directions, placing each slice on a baking sheet.
4 pieces frozen Texas Toast garlic bread
In a saucepan, heat the frozen meatballs with the marinara sauce until the meatballs are no longer frozen. Turn the heat down until you're ready to assemble the sandwich.
12 precooked meatballs, 10 ounces marinara sauce
Remove the garlic toast from the oven and, using a spoon, gently press down around the crust to make an indentation in the toast. Add 3 meatballs and sauce to each slice of toast. Top each toast with a slice of Provolone cheese.
4 slices Provolone cheese
Return the sheet pan to the oven to melt the cheese. Once melted, remove from the oven and serve.