Salmon, Asparagus, and Leek in Parchment

Preheat oven to 400 degrees with racks in upper and lower thirds. Cut four 12-by-17-inch pieces of parchment. Fold each in half crosswise to make a crease, then unfold and lay flat. Toss asparagus and leek with oil in a bowl. Season with salt and pepper.

Season fish with salt and pepper. Arrange a fillet on one side of crease on each piece of parchment. Top with asparagus mixture, dividing evenly. Fold each piece of parchment over, then make small overlapping pleats to seal open sides, creating half-moon-shaped packets.

Bake on 2 rimmed baking sheets, 10 minutes for medium-rare. Transfer to plates and carefully cut packets open with kitchen shears (steam will be released). Serve, topped with herbs and squeezed with lemon wedges.