• 4 tbsp. unsalted butter, softened to room temperature
Preheat the oven to 350 degrees. Cut 4 (12- by 24-inch) pieces of parchment paper.
Rinse the fillets and pat dry with paper towels. Place 1 walleye fillet at one wide end of the parchment, leaving about 2 inches of paper uncovered at the bottom. Put 2 slices of lemon, 1 or 2 dill sprigs, and 1 or 2 parsley sprigs on top of each fillet. Shake 2 dashes of Tabasco over each fillet. Season with salt and pepper. Dot each fillet with a tablespoon of butter.
To close the parchment paper, moisten the edges of the paper with water. Fold the free half of the paper over the fish, closing it like a book. Fold the edges of the paper over, crimping as you go, to enclose the fish. Assemble the remaining 3 packets, and place all the packets on a baking sheet.
Bake until the parchment paper is puffed and brown, 8 to 10 minutes.