Preheat oven to 400°F. Grease a baking sheet with non stick spray or dab of extra virgin olive oil.

Using a damp kitchen towel or paper towel, wipe the the mushrooms clean of any grit. Trim off the tough bottoms of each stem. Carefully remove the stems and set aside. We are going to stuff the caps, so be sure to keep them intact.

Chop up the reserved stems and add them to a medium sized bowl with the egg, bread crumbs, Parmesan cheese and garlic. Toss to combine and then season to taste with kosher salt and freshly ground black pepper. Stir in enough extra virgin olive oil to make the mixture glisten. You want the stuffing coated, but not swimming in olive oil.

Stuff each mushroom cap with a good spoonful of the stem mixture. Place the stuffed caps, stuffed side up on the prepared baking sheet. Transfer to the preheated oven and cook until the tops are lightly golden brown (about 15 minutes).

Let the mushrooms cool a minute or two before serving.