Preparation Rinse dried porcini to remove any grit. Place porcini and wine in small saucepan. Bring to simmer over low heat; remove from heat. Let soak until soft, about 20 minutes. Using slotted spoon, transfer porcini to work surface and coarsely chop. Line strainer with damp paper towel; strain wine into small bowl and reserve. Melt butter in heavy large skillet over medium-high heat. Add crimini and shiitakes. Sprinkle with salt and pepper and cook until brown, stirring occasionally, about 8 minutes. Add shallot and stir until soft, about 1 minute. Add chopped porcini and strained wine. Boil until almost dry, about 1 minute. Stir in thyme. Season to taste with salt and pepper. Cool. Remove Brie from box, discarding lid and paper. Using sharp knife, cut top rind from Brie; discard. Return Brie to box. (Alternatively, stack two 12-inch rounds of foil and fold up around bottom and sides of Brie, crimping foil at edges, leaving top exposed.) Mound mushroom mixture atop Brie. DO AHEAD: Can be made 8 hours ahead. Cover and chill. Bring to room temperature before continuing. Preheat oven to 350°F. Place Brie with mushrooms on rimmed baking sheet. Bake until cheese begins to melt and mushrooms are warmed through, about 15 minutes. Transfer Brie in box to plate. Serve hot with baguette slices. *Available in the produce section of many supermarkets and at specialty foods stores and Italian markets. Test-kitchen tip:To cut the top off the round of Brie more easily, first place the cheese in the freezer for a few minutes to firm it up slightly.
Preparation Rinse dried porcini to remove any grit. Place porcini and wine in small saucepan. Bring to simmer over low heat; remove from heat. Let soak until soft, about 20 minutes. Using slotted spoon, transfer porcini to work surface and coarsely chop. Line strainer with damp paper towel; strain wine into small bowl and reserve. Melt butter in heavy large skillet over medium-high heat. Add crimini and shiitakes. Sprinkle with salt and pepper and cook until brown, stirring occasionally, about 8 minutes. Add shallot and stir until soft, about 1 minute. Add chopped porcini and strained wine. Boil until almost dry, about 1 minute. Stir in thyme. Season to taste with salt and pepper. Cool. Remove Brie from box, discarding lid and paper. Using sharp knife, cut top rind from Brie; discard. Return Brie to box. (Alternatively, stack two 12-inch rounds of foil and fold up around bottom and sides of Brie, crimping foil at edges, leaving top exposed.) Mound mushroom mixture atop Brie. DO AHEAD: Can be made 8 hours ahead. Cover and chill. Bring to room temperature before continuing. Preheat oven to 350°F. Place Brie with mushrooms on rimmed baking sheet. Bake until cheese begins to melt and mushrooms are warmed through, about 15 minutes. Transfer Brie in box to plate. Serve hot with baguette slices. *Available in the produce section of many supermarkets and at specialty foods stores and Italian markets. Test-kitchen tip:To cut the top off the round of Brie more easily, first place the cheese in the freezer for a few minutes to firm it up slightly.