En papillote

Papillote means a greased usually paper wrapper in which food (such as meat or fish) is cooked. En papillote is method that uses steam to gently cook chicken, vegetables, and fish. Cooking en papillote offers home cooks an elegant way to prepare and present delicate foods.

In the culinary arts, the term en papillote refers to a moist-heat cooking method where the food is wrapped in a packet of parchment (or foil), and then cooked in the oven. The enclosed parcel traps in any moisture released while cooking, resulting in tender, juicy flesh which is part steamed, part baked.

Fish fillets are the classic choice for the en papillote method, since they can so easily overcook while roasting or searing. Fish cooked en papillote, which means wrapped in a packet of parchment (or foil), is a dramatic way to procure perfectly cooked salmon.

When cooking en papillote, there are usually vegetables, herbs, and seasonings included in the packet along with the main item. These additional ingredients, along with the main item, give off steam, which is what actually cooks the food.
En papillote