Looking to cut down on fat and calories? Cooking food in a packet is one of the best ways to keep the flavor locked in, and cleanup couldn't be easier.
Preheat oven to 450 degrees. Heat oil in a large sauté pan and cook chard, carrots, celery, and half of scallions until soft, about 8 minutes. Let cool slightly, then toss with orange juice and zest. Season to taste with salt and pepper and set aside. Cut a 2-foot length of parchment paper (or foil) and place on a sheet pan. Spoon about 2 tablespoons vegetable mixture onto each fish fillet. Gently roll each fillet and secure with toothpicks. Arrange fillets on 1/2 of the paper. Sprinkle with pepper, top with lemon slices and any remaining sauce. Fold paper in half and crimp edges until well sealed. Bake 12 to 18 minutes until fish is opaque. Remove rolls and sprinkle with remaining scallions. Remove toothpicks. Serve.