1️⃣ Preheat oven to grill/broil settings on high heat. Arrange the oven shelf to the middle of your oven. 🔥

2️⃣ Combine all of the Garlic Butter ingredients together in a small saucepan (or microwave-safe bowl), and melt until garlic is fragrant. 🧄🧈

3️⃣ Brush the bottoms of each mushroom and place them, buttered side down, on a baking tray. 🍄

4️⃣ Flip and brush any remaining garlic butter over the insides of each cap. Fill each mushroom with the mozzarella slices and tomatoes. 🧀🍅

5️⃣ Grill/broil until the cheese has melted and is golden in color (about 8 minutes). ⏲️

6️⃣ To serve, top with fresh basil, drizzle with balsamic glaze, and sprinkle with salt to taste. 🌿🍇🧂

Balsamic Glaze:

7️⃣ If making from scratch, prepare while mushrooms are in the oven. Combine sugar (if using) and vinegar in a small saucepan over high heat and bring to a boil. Reduce heat to low; allow to simmer for 5-8 minutes or until mixture has thickened and reduced to a glaze. If not using sugar, allow to reduce for 12-15 minutes on low heat. 🍇🍬