Feta-Walnut Stuffed Mushrooms

1 . Stage

Preheat the oven to 400° with a rack in the center position. Carefully remove the stems from the mushroom caps and finely chop; set the caps aside. 

2 . Stage

Place 2 tablespoons oil in a skillet and heat on high until shimmering. Add the chopped mushroom stems and cook until golden, 3 to 5 minutes. Reduce heat to medium and add the shallot, garlic, and a pinch of salt; cook until the shallots have softened, about 1 minute. Add the breadcrumbs and cook until toasted, about 2 minutes. Off heat, stir in the feta, walnuts, and parsley. Season with salt and pepper to taste. 

3 . Stage

Place the mushroom caps stem-side-up on a rimmed baking sheet and season with salt and pepper. Fill the cavities with the stuffing mixture.

4 . Stage

Bake until the mushrooms are tender and the filling is golden, about 20 minutes.