1/2 cup fresh shredded Mozzarella cheese
1/2 cup fresh shredded Gruyère
1/2 cup fresh grated Parmesan
2 tablespoons freshly chopped parsley, plus more for garnish
2 teaspoons Italian seasoning, (or dried Italian mixed herbs)
1/2 teaspoon onion powder
1/2 teaspoon garlic powder
8 large portobello mushrooms
Salt, to season
Cracked black pepper, to taste
1/2 cup heavy cream
2 cloves garlic minced (or 2 teaspoons minced garlic)
Preheat oven to 400°F (200°C). In a medium bowl, toss together Mozzarella, Gruyère, Parmesan, parsley, Italian seasoning, onion powder and garlic powder. Set aside.
Remove stems from portobello mushrooms and slice into 1/2-inch (1-cm) slices.
Arrange one-third of mushrooms in the bottom of a 2-quart (2-litre) baking dish. Sprinkle with one-third of the cheese mixture. Season with salt and pepper.
Repeat layering two more times.
Mix together cream and minced garlic and pour mixture over mushrooms.
Cover with foil and bake until mushrooms are tender, (about 30 minutes). Remove foil and carefully pour out excess liquid from the bottom of the dish into a small pot. Set pot aside.
Return mushrooms to the oven and broil/grill until golden, (about 4-5 minutes).