|Prep time: 20 minutes||Cooking time: 20 minutes||Total time: 40 minutes|
1. Heat broiler with rack 4 inches from flame. On a rimmed baking sheet lines with foil, toss broccoli with oil, season with course salt & pepper. Broil tossing once or twice until broccoli begins to char, 4 to 6 minutes.
2. Add mushrooms and peppers to broccoli, season with with salt and pepper, toss to combine. Broil tossing once or twice until veggies are tender, 8 to 10 minutes. Set aside.
3. Meanwhile, in a small bowl, combine mayo and garlic, season with salt and pepper. Place bread on work surface. Dividing evenly, spread with mayo and top with vegetables, then cheese. Place on baking sheet and broil until cheese is melted and lightly browned, 1 minute or so.