Parboil

To parboil is to partly cook food in boiling water, then finish cooking it another way. It is used when food would take too long to cook through by the second method, or when you want a softer outside that crisps well. Potatoes for roasting, carrots and parsnips, ribs before grilling, and rice for biryani are often parboiled. It is longer than blanching, which only cooks the surface.

How to do it

1. Cut the food into even pieces.
2. Put potatoes and other root vegetables into cold, salted water. Put green vegetables and rice into water that is already at a full boil.
3. Bring to a boil and cook until the outside is soft but the middle is still firm. This is usually 5 to 10 minutes for potato chunks and 3 to 5 for carrots.
4. Drain well. For potatoes, let them steam dry in the colander for a few minutes, then shake to rough up the edges.
5. Finish cooking: roast, fry, grill or bake. If you are not cooking them straight away, cool them quickly in cold water and chill.

How to tell it is done

A knife goes into the outer part easily but meets resistance in the center. Potatoes look fluffy at the edges but hold their shape. They should not be fork-tender yet.

Why it works

Boiling water heats food faster and more evenly than an oven, so it starts cooking the middle quickly. On potatoes, it softens the surface starch. Once roughed up and roasted, the starchy outside dries into a thick, crisp crust.

Common mistakes

• Cooking too long. The food falls apart or turns mushy in the second step.
• Not draining well. Wet potatoes steam in the oven and do not crisp.
• Leaving parboiled food warm for hours. If you are not finishing it within the hour, cool it fast and refrigerate it.
• Starting potatoes in boiling water. The outside cooks well before the inside.

In recipes

"Parboil for 5 minutes, then drain" is the usual form. Parboiled rice, also sold as converted rice, is different: it is steamed in the husk before milling and is sold ready to cook.