1. Preheat the oven

Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it with olive oil.

2. Prepare the mushrooms

Clean the portobello mushrooms by wiping them gently with a damp paper towel to remove any dirt. Remove the stems and use a spoon to scrape out the gills if desired (this step is optional but helps reduce moisture and create more space for the filling).

3. Season the mushrooms

Place the mushrooms on the prepared baking sheet, cap side down. Drizzle 1 tablespoon of olive oil over the mushrooms and season with ¼ teaspoon of salt and ¼ teaspoon of black pepper. Bake for 8-10 minutes to soften the mushrooms slightly and release excess moisture. Remove from the oven and pat the inside of each mushroom dry with a paper towel if needed.

4. Prepare the filling

In a medium mixing bowl, combine the halved cherry tomatoes, mozzarella balls, chopped basil, remaining 1 tablespoon of olive oil, Italian seasoning, and the remaining ¼ teaspoon of salt and black pepper. Toss gently to coat the ingredients evenly.

5. Stuff the mushrooms

Divide the tomato and mozzarella mixture evenly among the mushroom caps, filling each one generously. Sprinkle grated Parmesan cheese on top if desired for extra flavor and a slightly crispy topping.

6. Bake the mushrooms

Return the stuffed mushrooms to the oven and bake for an additional 10-12 minutes, or until the mozzarella is melted and bubbly.

7. Drizzle with balsamic glaze

Remove the mushrooms from the oven and drizzle with balsamic glaze. Garnish with additional fresh basil leaves and red pepper flakes if desired.

8. Serve immediately

Serve the Caprese stuffed portobello mushrooms hot as an appetizer, side dish, or light main course. Pair with a crisp salad, crusty bread, or a simple pasta dish for a complete meal.