I have a different stuffed mushroom recipe that takes a while to prepare but is well worth the effort.
You need:
15 large mushrooms
1 small onion
1 clove of garlic
1 chunk of bacon or some pre-cut bacon pieces
a tablespoon of olive oil
a dessert-spoonful of cognac/brandy
1 egg
cream
grated parmesan cheese
breadcrumbs
Wash the mushrooms and remove the stalks. Place the mushrooms belly up on a tray and put in the oven at about 175 degrees.
Dice up the onion and garlic and place in a pan with the olive oil. Let them get golden and then add the also diced bacon chunk/ pre-cut bacon pieces. After those are fried add the chopped up stalks.
Check on the mushrooms in the oven, they will be full of water, you need to pour that out. Put them back in the oven.
When everything i golden and smelling wonderful, add the cognac/brandy and let the alcohol cook off. If your pan is shallow enough, try flambéing it for extra taste.
After this, add a mixture of the egg, some cream, and part of the parmesan.
Mix fast and well so it doesn't go overly lumpy.
Take out the mushrooms from the oven and strain one more time. Then, top them with the stuffing mixture, and sprinkle that with the leftover parmesan mixed with breadcrumbs for texture.
Grill in the oven for 5-10 mins and serve.
Yummy stuff!