En papillote

En papillote is French for in paper. It means cooking food sealed inside a parcel of parchment paper (baking paper in the UK) or foil. In the oven, the moisture from the food and any wine, butter or citrus you add turns to steam, which cooks everything gently. It is mostly used for fish fillets, shellfish, chicken breast and thinly cut vegetables. In Italian the method is called al cartoccio.

How to do it

1. Heat the oven to 200°C (400°F).
2. Cut a sheet of parchment about 40 cm (16 inches) long for each portion. Fold it in half and cut a large half-heart shape, so it opens into a heart.
3. Lay a bed of thin vegetables near the fold. Julienne carrots, leeks, fennel or zucchini (courgette in the UK) so they cook as fast as the fish.
4. Put the fish on top. Season it and add a knob of butter or a drizzle of oil, herbs, citrus slices and a splash of wine.
5. Fold the paper over. Starting at the top of the heart, make small, overlapping folds along the edge, pressing each one, until the parcel is sealed. Twist the tip.
6. Bake on a sheet pan for 10 to 15 minutes for fillets 2 to 3 cm (about 1 inch) thick.
7. Serve the parcels closed and let each person cut theirs open. Mind the steam.

How to tell it is done

The parcel puffs up in the oven. Fish is opaque and flakes when pressed. Because you cannot see inside, push a thermometer through the paper: 63°C (145°F) in the thickest part.

Why it works

The sealed paper holds in moisture, so the food steams in its own juices and the herbs and wine. Nothing dries out, and the juices make a light sauce in the bottom of the parcel.

Common mistakes

• Folds that are not tight. Steam escapes and the food dries.
• Thick vegetables. They are still raw when the fish is done.
• Too much liquid. A tablespoon or two is enough. The food releases its own.
• Using wax paper. It is not ovenproof. Use parchment or foil.
• Very acidic sauces in foil. Acids can react with aluminum. Line the foil with parchment.