Preheat an oven to 300°F

Carefully wash the mushrooms and remove the stem. The soft part of the stem, cut it in brunoise and reserve, discard the rest.

Spray 8-inch (20 cm) non-stick skillet with cooking spray and heat over medium-high heat. Add the bacon, garlic and onion until toasted.

In a mixing bowl, add the egg, the stem chopped, coriander, chopped cheese and toasted onion, and bacon.

Using a little spoon, fill each mushroom cap with a generous amount of stuffing.

Bake until the mushrooms are golden on top, about 25 minutes. Serve.