Loaded Grilled Roast Beef Sandwich

large red onion, thinly sliced

green bell peppers, cored, sliced into batons

garlic cloves, roughly chopped

Olive oil

Seasoned salt

brandy

slices good French boule bread or similar

Unsalted butter, softened

slices mozzarella cheese

sharp cheddar cheese, shredded

thinly sliced rare roast beef (deli roast beef is fine), divided into four equal portions

large tomato, sliced