4 6-inch Portobello mushroom caps
4 cups spinach
1 cup breadcrumbs
1 cup shredded mozzarella cheese
1 shallot (1 finely chopped)
1 large tomato, diced (I did canned tomatoes)
3 tablespoons grated Parmesan Cheese
3 tablespoons extra-virgin olive oil, plus more for drizzling
Kosher salt and freshly ground pepper
1/2 cup ricotta cheese
Preheat the broiler. Mist a foil-lined broiler pan with cooking spray. Put the mushrooms gill-side down on the pan; broil 5 minutes.
Remove the mushrooms from the broiler and turn them gill-side up on the pan. Season with salt and pepper. Mound the spinach filling on the mushrooms and top with the ricotta. Sprinkle with the remaining 1 tablespoon Parmesan and broil until the filling is heated through and the ricotta is lightly browned, about 5 minutes.