- 18 Crimini mushrooms, centers popped out, bottoms trimmed for leveling, and tossed in olive oil. Place holes up on baking pan.
For the stuffing:
- 2 cups breadcrumbs or leftover stuffing
- 2 cups total shredded Fontina, Parmesan, Asiago and crumbled Feta (these are suggestions; cheeses can be substituted)
- 1/4 cup each chopped fresh basil, oregano, parsley and chives
- 1 red onion, finely diced
- 2 tablespoons fresh garlic
- 2 tablespoons olive oil, plus more for drizzling
- Salt and pepper
- 1 cup red wine
- 1 large egg, beaten
- 1 cup balsamic vinegar
Preheat oven to 400° F.
Break up breadcrumbs or stuffing into a bowl. Add 1 1/2 cups of the cheese and chopped fresh herbs; mix well. Sauté onion and garlic in 2 tablespoons olive oil. Season with salt and pepper. When the onion mixture is softened, add red wine and reduce. Combine with the breadcrumb mixture. Cool, then add egg and mix well.
Heat the balsamic vinegar in saucepan on medium-low heat. Fill each mushroom with stuffing and place on a rimmed baking sheet. Drizzle with olive oil and sprinkle with remaining 1/2 cup cheese. Bake until stuffing is golden brown on top, about 15 minutes.
Turn heat off the balsamic vinegar. You can speed up the cooling by swirling the vinegar around in the saucepan; it will thicken as it cools. Drizzle over the mushrooms before serving.
Serve mushrooms hot or at room temperature. (Can be made 2 hours ahead; let stand covered at room temperature.)