Preheat the oven to 400°F. Bring a large pot of salted water to a boil.

Clean mushrooms off and scoop out insides and stem, reserving mushroom pieces in small bowl.

Rub the mushrooms all over with 1 tablespoon of the olive oil and season with salt and pepper. Place the mushrooms cap-side down on a baking sheet. Bake 10 minutes.

Meanwhile, add the orzo to the boiling water. Cook according to package directions until al dente (usually 9 minutes). Drain the orzo, and return back to pot. Add 6 oz of pesto, red pepper flakes, salt and pepper. Add reserved mushroom pieces. Stir well.

Remove mushrooms from oven. Flip mushrooms over and bake another 10 minutes.

Remove the mushrooms from the oven and carefully spoon orzo evenly among the mushrooms.

Top with mozzarella cheese and pine nuts.

Bake mushrooms 5 minutes. Turn on the broiler and cook until the cheese is melted and bubbling, 3-4 minutes longer.

To serve, spoon the mushrooms onto plates. Top each plate with fresh basil.