While panko (Japanese) breadcrumbs (available in the Asian foods aisle at most supermarkets) work best in this meatless main dish, you can substitute freshly made coarse breadcrumbs, if necessary. Two colors of tomato give it a nice presentation, but you can use all red or yellow, too.
4 (6-inch) portobello mushrooms, stems removed
1 cup chopped red tomato
1 cup chopped yellow tomato
1 cup panko (Japanese) breadcrumbs
1 cup (4 ounces) preshredded part-skim mozzarella cheese
1/4 cup chopped fresh chives
1/4 teaspoon salt
1/4 teaspoon black pepper
How to Make It
Remove brown gills from the undersides of mushrooms using a spoon; discard gills. Place mushrooms, gill sides down, on a foil-lined baking sheet coated with cooking spray. Broil the mushrooms for 5 minutes.
While mushrooms broil, combine the tomatoes, panko breadcrumbs, cheese, and chives.
Turn mushrooms over, and sprinkle evenly with salt and pepper. Divide tomato mixture evenly among mushrooms. Broil 5 minutes or until cheese melts.