A flavorful appetizer, side, or vegetarian main dish.
Preheat oven to 425°F (220°C).
Clean mushrooms with a damp paper towel. Remove stems, chop finely, and set aside.
Heat 1 top olive oil in a skillet over medium heat. Sauté garlic for 1-2 minutes until fragrant. Add spinach and chopped mushroom stems; cook 2-3 minutes until wilted.
Cool slightly.
Mix ricotta, mozzarella, sun-dried tomatoes, and spinach mixture in a bowl. Season with salt and pepper.
Place mushroom caps on a parchment-lined baking sheet. Brush with olive oil. Fill each cap with the ricotta mixture.
Mix crumb topping ingredients and sprinkle over mushrooms.
Bake for 10 minutes. If crumbs aren't golden, broil briefly, watching closely to avoid burning.