Sausage-Stuffed Portobello Mushroom Caps

Adapted from The Food Network.

Sausage-Stuffed Portobello Mushroom Caps
Ingredients
3 Portobello mushroom caps (1 package)
1 teaspoon plus 1 teaspoon extra-virgin olive oil, plus more for drizzling
12 ounces hot and/or sweet Italian sausage
¼ cup finely chopped onion
¼ cup finely chopped green bell pepper
⅛ cup finely chopped celery
1 teaspoon minced garlic
¼ cup plain bread crumbs
¼ cup freshly grated Parmesan
⅛ cup plus 1 tablespoon minced fresh parsley leaves
1 teaspoons spice mix (see recipe below)
1 egg, lightly beaten
Balsamic vinegar, for drizzling

Directions
1. Preheat the oven to 400 degrees.
2. Using your hands, lightly rub mushroom caps with 1 tablespoon olive oil.
3. Cook the sausage in a medium skillet until browned, about 4 minutes. Add the onion, bell pepper, and celery and cook until softened, about 3 minutes. Add the garlic and cook until fragrant, about 30 seconds. Remove from heat.
4. Transfer sausage-vegetable mixture into a food processor. Add half of the bread crumbs and grated Parmesan, ⅛ cup parsley, spice mix, and the remaining teaspoon of olive oil. Pulse until mixture is finely chopped and comes together slightly, about 30 seconds. Transfer the mixture to a bowl, add the egg, and stir until well combined.
5. Divide the filling among the mushroom caps, about ½ cup for each mushroom. Place the filled mushrooms on a baking sheet. Combine remaining bread crumbs Parmesan in a small mixing bowl. Divide the bread crumb mixture evenly among the tops of the mushrooms. Bake until golden brown on top and the mushrooms are tender, about 15 to 18 minutes. Remove from oven and let cool slightly. Garnish with remaining tablespoon of parsley, drizzle with olive oil and vinegar and serve warm or at room temperature.

Spice Mix (The Food Network’s Creole Seasoning): 2½ tablespoons paprika, 2 tablespoons salt, 2 tablespoons garlic powder, 1 tablespoon black pepper. 1 tablespoon onion powder, 1 tablespoon cayenne pepper, 1 tablespoon dried oregano, and 1 tablespoon dried thyme.