Preheat Oven: Start by preheating your oven to 375°F (190°C).
Prepare Mushrooms: Gently clean the Portobello mushrooms with a damp cloth. Remove the stems and scrape out the gills if desired to create space for the filling.
Season the Caps: Place the mushroom caps on a baking sheet, stem side up. Drizzle with olive oil, and rub it evenly over the surface. Sprinkle with minced garlic, fresh thyme, rosemary, salt, and pepper.
Add Cheese: Top each mushroom with shredded mozzarella cheese. You can also sprinkle some extra herbs or a pinch of red pepper flakes for a little heat.
Bake: Place the mushrooms in the oven and bake for 20-25 minutes, or until the mushrooms are tender and the cheese is melted and golden.
Garnish & Serve: Remove the mushrooms from the oven and sprinkle with fresh parsley before serving.
Notes
For a crunchier topping, you can add breadcrumbs mixed with a little olive oil before baking.
The mushroom caps can be stuffed with other ingredients like sautéed spinach or cooked quinoa for a heartier meal.