Servings: (3-4 oz. fish and 1/2 cup vegetables per serving)
Preheat the oven to 425°F. Cut eight 15-inch-long sheets of cooking parchment or aluminum foil. Set aside.
Place the asparagus in the center of four of the parchment sheets. Place the carrot and leek on the asparagus. Place the fish on the vegetables. Sprinkle with the salt and pepper. Place a tarragon sprig on each piece of fish. Sprinkle with the chives. Drizzle with the oil.
Place one of the remaining four sheets of parchment over the fish. Fold the edges toward the center. Holding the tops together, fold several times to seal securely. Transfer the packets to a large rimmed baking sheet. (The packets can be made up to 6 hours in advance. Cover and refrigerate until baking time.)
Bake for 10 minutes. Remove from oven.
Using the tines of a fork, carefully open a packet away from you (to prevent steam burns). If the fish flakes easily when tested with a fork, carefully open the remaining packets and serve. If the fish isn't cooked enough, reclose the open packet and bake all the packets for 1 to 2 minutes more.
Note: Since everyone’s health history and nutritional needs are so different, please make sure that you talk with your doctor and a registered dietitian to get advice about the diet and exercise plan that‘s right for you.