Heat butter in a medium skillet over medium heat. Add shallot, and cook 1 to 2 minutes. Add porcini mushrooms and leftover mushroom stems from Golden Mushroom Caps, and cook 4 to 5 minutes. Add white wine, scraping up any bits that may be on the bottom of the pan, and cook until the wine has evaporated, 1 to 3 minutes. Season with salt and pepper, to taste, and remove from the heat.
Set rack in the center of the oven, and set oven on broil. Use a small spoon to fill each mushroom cap with the filling. Place the caps on a baking sheet, and set aside.
Slice Camembert into 24 small pieces, making each slice just large enough to cover about half of the filling. Set aside. Broil the filled mushroom caps until hot throughout, 2 to 3 minutes. Remove, and place a cheese slice on each mushroom. Serve hot.
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