Cooking regime

Cooking inside something

Wrapping food in salt, pastry, clay, foil, leaves or paper changes what the heat does. The shell moderates the heat, traps the moisture and aroma, and the food effectively steams in its own juices at a very steady temperature.

The shell does three things at once

First, it slows and evens the heat. The oven's temperature swings and hot spots are absorbed by the shell, and what reaches the food is steadier and gentler than the oven setting suggests.

Second, it traps moisture. The food releases steam that cannot escape, so it cooks in a saturated atmosphere and stays far moister than it would uncovered.

Third, it traps aroma. Everything volatile that would be lost to the oven stays inside, which is why opening a parcel at the table is a genuinely different experience from serving the same food off a tray.

The trade is that nothing browns inside a shell. These methods are for moisture and aroma, not for crust.

The forms it takes

En papillote

Baking parchment or foil, folded into a sealed parcel. Classically fish with aromatics, and excellent for vegetables and chicken breast.

Salt crust

A thick paste of salt and egg white encasing a whole fish or a joint. It does not make the food salty; it makes a rigid, insulating, sealed shell.

Pastry case

Beef Wellington, a whole fish in pastry, a raised pie. The pastry may or may not be eaten.

Clay pot

A soaked unglazed pot that releases steam slowly as it heats. Roman pots, tagines, Chinese sand pots.

Leaves

Banana leaf, vine leaf, corn husk, lotus leaf. They contribute aroma as well as enclosing.

Foil

The simplest version, and it works, though it contributes nothing of its own.

Dough or a sealed lid

A luted pot, sealed with a rope of flour-and-water paste. Old and effective.

Making a parcel that works

1. Cut a large piece of parchment or foil, much bigger than looks necessary. The parcel needs air space inside.
2. Put the food on one half, with the aromatics and a knob of fat or a splash of liquid.
3. Season properly. Nothing evaporates, so the seasoning cannot concentrate.
4. Fold the other half over and crimp the edges tightly in overlapping folds. The seal is the whole technique.
5. Leave a dome of air inside rather than wrapping it tight, so the steam has somewhere to circulate.
6. Bake in a hot oven. The parcel should inflate, which tells you it is sealed.
7. Take the timing from the thickness of the food, and remember that it will not brown so colour is no guide.
8. Open it at the table, or at least away from the oven, so the aroma is not wasted. Whether a food is safely cooked is a matter for a food safety authority rather than for a description of how the heat arrives. In the UK the Food Standards Agency sets that guidance and it is the one to follow.

What suits it and what does not

• Fish, which is the classic and the best. It stays moist and picks up every aromatic in the parcel.
• Lean chicken and pork, which benefit most from not drying out.
• Vegetables, especially in a mixture, where the aromatics circulate.
• Whole large fish in a salt crust, which is spectacular and much easier than it looks.
• Anything that wants a crust does not suit it. No browning happens inside a sealed shell.
• Anything with a lot of liquid will boil rather than steam, and the parcel becomes a bag of soup.
• Very long cooking suits clay and luted pots but not parchment.
• Combination: open the parcel for the last few minutes under a grill if you want colour as well.

Common questions