Clean the Portobello mushrooms by gently wiping them with a damp cloth. Remove the stems and scrape out the gills (if desired) for more space to stuff.
In a mixing bowl, combine the halved cherry tomatoes, mozzarella balls, torn basil leaves, minced garlic, and balsamic glaze. Toss gently to coat.
Drizzle olive oil over the Portobello caps and season with salt and pepper. Place them on a baking sheet, gill side up.
Generously fill each mushroom cap with the tomato and mozzarella mixture.
If desired, sprinkle grated Parmesan cheese on top of the stuffed mushrooms for an extra flavor boost.
Bake in the preheated oven for about 20-25 minutes, until the mushrooms are tender and the cheese is melted and bubbly.
Once done, remove from the oven and let them cool slightly before serving.
Notes
Serve on a vibrant platter, drizzling any remaining balsamic glaze over the stuffed mushrooms. Garnish with extra basil leaves for a fresh touch.