Stuffed Mushrooms

Makes 12 mushrooms, 3 or 4 portions

12 medium-size mushroom caps
1 tablespoon olive oil
1 tablespoon unsalted butter
½ cup finely chopped yellow onion
2 tablespoons coarsely chopped walnuts
1 garlic clove, peeled and minced
5 ounces frozen chopped spinach, thoroughly defrosted and squeezed dry
1 ounce feta cheese, crumbled
1 ounce Gruyere cheese, crumbled
2 tablespoons minced fresh dill
Salt and freshly ground black pepper, to taste


1. Remove the mushroom stems and save for another use. Wipe the mushroom caps with a damp paper towel and set aside.
2. Heat the olive oil and butter together in a small skillet, over medium heat. Add the onion and cook, covered, until tender and lightly colored, about 25 minutes.
3. Preheat oven to 4000 F.
4. Add the walnuts and garlic to the onion and cook for another minute. Add the spinach and cook for another 5 minutes, stirring constantly. Remove from the heat and cool slightly. Stir in the cheeses, dill, salt, and pepper.
5. Arrange the mushrooms, cavity side up, in a baking dish. Divide the spinach mixture evenly among the mushroom caps.
6. Set the baking dish on a rack in the upper third of the oven. Bake until the filling is browned and the mushrooms are thoroughly heated, 8 to 10 minutes. Serve immediately.