Mushrooms should be stored in a breathable ... crushed garlic, herbs and seasoning and cook for a few minutes until the juices run, or slice thickly and sauté with onions and garlic.
Taste for seasoning. Lightly brush the mushrooms with oil and a pinch of salt. Spoon the filling into the cavities. Combine the remaining 2 tablespoons Parmigiano-Reggiano and the panko in a bowl.