How Long to Cook Salmon en Papillote
A normal-sized salmon fillet en papillote will only need to cook for 10 to 12 minutes. Always make sure to check the flakiness at the center of the fillet or check the internal temperature before eating, though: A larger fillet might need to cook for 15 or 20 minutes.
"En papillote" is French for "in parchment," and cooking salmon en papillote allows it to steam with whatever herbs or other seasonings you include in the pouch with it. This creates flaky and flavorful salmon and allows for easy cleanup, too. Foil makes a good substitute if you don't have parchment paper handy to make your cooking pouch.