Mushrooms Stuffed With Spinach and Walnuts
- Wipe mushroom caps with damp cloth and set aside.
- Heat olive oil and butter together in a small skillet. Add onion and cook over medium heat, covered, until tender and lightly colored.
- Preheat oven to 400 degrees Fahrenheit.
- Add walnuts and garlic to onion and cook for another minute. Add spinach (defrosted and squeezed dry) and cook for 5 minutes, stirring constantly. Stir in crumbled cheeses, dill, and salt and pepper.
- Arrange mushrooms, cavity side up, in a baking dish. Divide spinach mixture among them.
- Set baking dish in upper third of oven. Bake 8-10 minutes, until filling is browned and mushrooms are heated through. Serve immediately.