4-6 large portabello mushrooms
3 cloves garlic, minced
1½ tbsp. olive oil
Coarsely ground salt and pepper, to taste
1 cup ricotta cheese
1 large egg, lightly beaten
¼ cup grated Parmesan cheese*
6 oz. mozzarella cheese, shredded, divided*
2/3 cup drained frozen chopped spinach
½ tsp. Italian seasoning
1 cup tomato sauce
Preheat the oven to 425˚ F. Line a rimmed baking sheet with foil. Remove the stems from the mushrooms and carefully scrape the gills from the caps with a spoon or paring knife; discard. Place the mushrooms caps on the baking sheet. In a small bowl, combine the garlic and olive oil. Brush the garlic-oil mixture over the inside of the mushroom caps. Season with salt and pepper to taste. Roast the caps about 10 minutes. Remove from the oven, maintaining the oven temperature. If excess liquid has collected inside or underneath the caps, blot it away with a paper towel.
Meanwhile, in a medium mixing bowl, combine the ricotta, egg, Parmesan, about ¾ of the mozzarella, spinach, and Italian seasoning. Season with salt and pepper. Mix until evenly incorporated. Divide the mixture into the roasted portabello caps, spreading gently to fill them evenly. Top each with 1-2 tablespoons of the tomato sauce. Sprinkle the tops with the remaining shredded mozzarella.
Return to the oven and bake 10-15 minutes more, until the cheese is melted and the filling is warmed through. Serve with additional tomato sauce, as desired.
*For best results, always use freshly shredded cheese. Pre-shredded cheese comes coated in things such as flour, cornstarch to prevent clumping and results in an unpleasant, gritty texture when melted.