To keep the mushrooms from getting soggy, form four small rings out of aluminum foil. Then place them on a cookie sheet, and put mushroom caps on top. The foil rings will help the mushrooms roast more evenly as well.
Drizzle the portobello caps with olive oil, and sprinkle with salt and pepper.
Sprinkle a handful of mozzarella onto each mushroom cap, then top with a few slices of tomato and a sprinkling of basil. Then finish with another handful of mozzarella.
Bake at 375 °F for 20 to 25 minutes, until mushrooms have softened and cheese has melted.
Garnish with more basil, and serve immediately.
Price Per Serving
based on average national price: excludes store savings and local grocery store pricing