1/4 cup mayonnaise
2 tablespoons roasted red pepper, finely chopped
4 (3- to 4-inch) portabella mushrooms, stems and gills removed
4 (1/2-inch thick ) slices red onion
1 small zucchini, cut crosswise then lengthwise into 8 (1/4 inch thick) slices
4 (1/2-inch thick) slices fresh mozzarella cheese
8 slices 9-grain artisan bread, toasted
- To clean mushrooms, wipe with paper towel. Use spoon to scoop out gills under cap of each mushroom; discard gills.
- If mushrooms are too large, trim to fit bread.