Preheat the oven to 425F.
Slice mushrooms into 1/4-innch pieces and place in a mixing bowl with chopped anchovies, parsley, garlic, breadcrumbs, olive oil, lemonjuice and zest, and porcini powder, and toss to mix well. Seasonwith 3 tablespoons freshly ground black pepper, 2 tablespoons Maldon salt.
Lightly brush some olive oil on each sheet of paper. Divide the mushroom mixture among the parchment pieces and fold to form a cartoccio, like a love letter. Place on rack in the oven and cook the mushrooms for 6 minutes.
Serve the package on a warm platter. Slice an “X” with a sharp knife into each package tableside and allow guest to open to the magnificent fungal facial.