3 tablespoons extra-virgin olive oil, plus extra for greasing the grill pan
4 to 6 portobello mushrooms
1/2 teaspoon salt
1/4 teaspoon freshly ground black pepper
1 cup marinara sauce (store bought or homemade)
1/2 cup shredded mozzarella cheese
1/4 cup grated Parmesan
2 tablespoons butter, cut into small pieces

Place a grill pan over medium-high heat or preheat a gas or charcoal grill.

Drizzle 3 tablespoons of olive oil over both sides of the mushrooms. Sprinkle the mushrooms with salt and pepper. Drizzle olive oil on the grill to prevent the mushrooms from sticking. Grill until the mushrooms are heated through and tender, about 5 minutes per side.

Preheat the oven to 400 degrees F.

Spread 1/2 cup of the marinara sauce on the bottom of a 9 by 13-inch baking dish. Place the grilled mushrooms on top of the marinara sauce and top with the remaining marinara sauce. Sprinkle with the cheeses and top with the butter pieces. Bake until the cheese melts and the top is golden, about 15 minutes. Serve.