En Papillote

Preheat the oven to 425 degrees F. Mix the seasonings (vinegar, juice, wine, zest, spices, etc.) together in a small bowl; set aside. Fold 4 (20-inch) parchment paper squares in 1/2 lengthwise and cut out a large heart shape. Unfold and arrange on 2 baking sheets. Cook's Note: Aluminum foil can be substituted for parchment paper. Evenly divide the vegetables among the 4 heart-shaped parchment packets. Place fish fillet on top of vegetables and season. Top with a small pat of butter. Fold the top half of the parchment over the fish, overlapping small folds along the edges and sealing. Bake for 10 to 15 minutes, until the parchment paper puffs up. Transfer the parchment packets to plates. Carefully cut the packets open, avoiding the hot steam and serve.