1/4 cup all-purpose flour
1/2 teaspoon baking powder
5 large white mushrooms, sliced
In a medium bowl, mix flour, baking powder and mushrooms. Cover bowl with plastic wrap and refrigerate overnight.
The next morning, preheat oven to 350 degrees F (175 degrees C).
Place mushrooms on a large baking sheet. Sprinkle with 1/3 cup flour, creating a crust about 1/4 inch thick.
Bake at 350 degrees F (175 degrees C) for 1 1 hour, pressing down slightly. Add more flour, forcing through all of it. Reduce heat to 350 degrees F (175 degrees C) and bake 10 minute longer, or until mushroom is cooked thru, stirring every 5 minutes.