Cooking en papillote–in butterfly. It’s a lovely French term for a lovely French technique: wrapping food and flavorings in packets of parchment paper and baking them at high heat for a relatively brief time. The paper is cut into folded shapes like legless butterflies or enormous Valentines, then folded over a mound of raw ingredients and gently crimped around the edges. Then it goes into the oven, where the bits and pieces inside release their juices into fragrant vapor, trapped inside the packet, and delicately steam themselves. The process of cutting and assembling the packets is a bit elaborate, but they steam in a matter of minutes.
Vegetables and poultry take well to this method, I’m told, but every source I look at says the same: en papillote cooking really sings with fish. For sturdy, flaky fillets that can easily go from sashimi to sawdust with a little too much heat, cooking in parchment is a foolproof way to keep them glistening and pearly with juice. Because they’re steaming in their own juices, these fish fillets come out profoundly more flavorful than they went in. Streamlined seasonings stay subtle, not bland; aggressive ingredients get infused into the flesh of the fish.
I tried this for the first time this weekend, for my father’s birthday dinner, with red snapper fillets on a bed of leeks and fennel. I deliberately kept the seasoning simple–lemon, thyme, a splash of wine and a thin ribbon of oil–and was rewarded with a meal that smelled like a restaurant and tasted like the sea. I’ve never been much for mild white fish like snapper, precisely because I thought it had no flavor–but it does, sweet and subtle and easily masked otherwise. The most challenging part of the whole process was gauging doneness; I’m not usually comfortable going on cooking times alone, but in this case it’s more or less required.
I’ve posted an approximate recipe for what I did below, but this is really just a guideline to be traced. Any combination of fish, shellfish, vegetables, aromatics, herbs and spices, stacked together with a gloss of fat and a little extra liquid, will work beautifully in butterfly. Next time I’m thinking maybe salmon, with a puttanesca-type mixture of cherry tomatoes, olives, and capers. Or maybe Asian-style soy-steamed trout. I’ll keep you posted.