Portobello, Broccoli and Red Pepper Melts

small head broccoli, cut into small florets

olive oil

Kosher salt and black pepper

portobello mushrooms (stems removed), sliced ½-inch thick

red bell peppers, seeded and sliced ½-inch thick

light mayonnaise

garlic, minced or pressed

thick slices country bread

provolone cheese, thinly sliced