Parchment paper is a darling of professional cooks, but it's great for the rest of us too. The pros use it to line baking pans, cover dishes, make patterns for cookies and cakes, and cook food en papillote, which just means wrapped in parchment paper. We love this last technique especially ― all you need to do is arrange ingredients on parchment, wrap them up, and pop the package into the oven.
Cooking in parchment creates maximum flavor with minimal use of oil or fat, because all aromas are sealed in, along with moisture, as the food cooks. It's particularly good for cooking fish, since it protects the delicate flesh from direct heat and ensures even and gentle cooking. The natural juices of the fish and the vegetables do the actual work of cooking, simply by creating steam.
Flavor combinations with fish are practically endless: herbs, flavored oils, lemon juice or wine, and thinly sliced vegetables can be substituted or added as you like.
How to make a parchment packet
The key to cooking en papillote starts with the shape of the paper. Fold a piece of parchment paper, about 2½ times the size of what you'll be cooking, in half and cut it into a half-heart shape. Unfold, fill one half with the ingredients, and fold the other half over to enclose. Starting at the top of the heart in the center of the dip, fold about ¼ in. of the edge toward the center and start rolling this "hem" around the edge, crimping the roll as you seal it. When the roll reaches the bottom tip of the heart, twist to seal. When using aluminum foil, simply fold foil over contents and crimp edges to seal.