Don't use button shrooms, get something abit bigger. The one's we used looked like button shrooms but were twice as big.

Take out the stems, then scrape out the everything you can to get more room for stuffing and chop up real fine, then sautee in Olive oil to soften.
4 good sized crappie filets, boiled off and chilled in fridge
use 1 cup of Panko Bream crumbs
1 cup grated Parm cheese
1/2 stick butter
1/2 to 1/3 cup olive oil
1/2 cup chopped green onion
1/2 cup Sauteed Shroom stems
dash salt
Black pepper and red pepper to taste.
I think I should have added 1 egg, I didn't but they were still fine. I'll try 1 egg next time.

Just mix all ingredients together and stuff inside scrap Shroom caps and cook at 375 for 15 minutes, then broil til the tops are brown. If someone tries this, let me know if you added an egg or not and how they turned out