Few things in life are better than sweet caramelized onions. Add cheese and mushrooms and you have a fancy and festive Thanksgiving appetizer the whole family will enjoy! Simply caramelize an onion, sauté chopped spinach, and stuff the mixture into fresh portobello mushrooms then bake! Then top each mushroom with Parmesan and mozzarella cheeses, and bake again until melted and golden brown. These Caramelized Onion and Spinach Stuffed Mushrooms topped with gooey cheese is sure to be a Thanksgiving hit!
Caramelized Onion and Spinach Stuffed Mushrooms
Ingredients
- 1 medium sized onion, peel removed and thinly sliced
- 1 tablespoon butter
- 1 teaspoon sugar
- 3 tablespoons olive oil
- 8 large Portabello mushrooms, stem removed
- 1/4 cup finely chopped spinach
- Salt and pepper, to taste
- 1/4 cup freshly grated Parmesan cheese
- 1/2 cup freshly grated mozzarella cheese
- Freshly parsley, for topping optional
Instructions
- Preheat the oven to 400 degrees F.
- Rub down each mushroom generously with olive oil.
- In a large nonstick skillet over medium heat add all of the onion slices, butter, and sugar. Stir gently and frequently until completely tender, about 8-10 minutes
- Add in the finely chopped spinach and sauté for another minute.
- Stuff the mushrooms full with the tender onion and spinach mixture. Season with salt and pepper.
- Combine the Parmesan and mozzarella cheese in a small bowl.
- Top each mushroom evenly with the cheese.
- Bake until golden brown and the cheese is melted for about 10-14 minutes. If the cheese is browning too quickly, top with a little bit of foil.
- Remove, allow to slightly cool, and top with fresh parsley.