Directions

1. Preheat the oven to 375° F. Line a baking sheet with parchment.
2. Remove the stems from the mushrooms. Finely chop the stems to yield 1/2 cup and set aside (discard the remainder). Lightly brush the mushroom caps with oil. Place the caps, rounded-side down, on the prepared baking sheet. Set aside.
3. To make the stuffing, melt the butter in a medium skillet over medium-high heat. Add the onion and cook, stirring occasionally, until fragrant, about 1 minute. Add the mushroom stems and garlic. Continue cooking, stirring occasionally, until the mushrooms and onion are tender, about 4 minutes.
4. Remove the pan from the heat. Stir in all the stuffing remaining ingredients, except the paprika. Taste and adjust the seasoning.
5. To serve, fill the mushroom caps with the stuffing and sprinkle with paprika. Bake for about 10 minutes, or until the stuffing is heated through and lightly browned.