Dust the surface with cornmeal then roll out the pizza dough, enough to fill your tray and almost overhang the edge.
Place the dough into the tray, then lay the cheese strings around the edge. Fold the overhanging dough over the cheese string and press it down - use a fork to get a strong seal.
Spread a thin layer of marinara sauce around the base.
Add the mozzarella slices, then the provolone.
Add another thin layer of tomato, the grated cheddar and mozzarella, and then the ground beef, green pepper and onion.