Preheat your oven to high grill or broil (about 500°F or 260°C). In a small saucepan, melt 2 tablespoons of butter over medium heat, adding 2 crushed garlic cloves. Stir until fragrant, about 1 minute.

Gently clean 4 large Portobello mushrooms with a damp paper towel and ensure they're dry. Place them stem-side up on a baking tray and brush the cooked garlic butter generously on the bottoms and insides.

Slice 8 ounces of fresh mozzarella cheese into thin rounds and halve 1 cup of grape tomatoes. Layer mozzarella slices and distribute the halved tomatoes evenly in each mushroom cap.

Place the stuffed mushrooms in the preheated oven and broil for about 8 minutes until the cheese melts and turns golden brown.

Remove the mushrooms from the oven, let them cool for a minute, top with shredded basil, and drizzle with balsamic glaze.