Greens, and how to stop overcooking them

Greens are the food group people most often say they should eat more of and least often enjoy.

Nearly always because of how they were cooked.

The categories

Different greens need different treatment, and the main variable is toughness.

Tender greens — spinach, rocket, watercress, young chard. Cook in seconds. Frequently better raw or barely wilted.

Sturdy greens — kale, cavolo nero, collards, mature chard, mustard greens. Need real cooking, and reward it.

Brassicas — broccoli, cauliflower, sprouts, cabbage. A different proposition again, and generally best roasted or seared rather than boiled.

Bitter greens — chicory, endive, dandelion, rapini. Bitterness is the point; manage it rather than eliminating it.

The techniques

Blanching. Large pot of well-salted boiling water, greens in briefly, out, into cold water to stop the cooking.

Preserves colour, removes some bitterness, and gives you greens ready to be finished in a pan.

The mistakes: not enough water, so the temperature drops; not enough salt; and leaving them in too long.

Sautéing. Hot pan, oil, garlic, greens, salt. Tender greens take a minute; sturdy ones take longer and benefit from a splash of water and a lid for a few minutes to steam through, then the lid off to drive off moisture.

Roasting. The technique that converts people. High heat, oil, salt, spread out so they are not crowded.

Broccoli, cauliflower, sprouts and kale all become something entirely different when roasted — sweet, browned, crisp at the edges.

The crowding point matters. Vegetables piled up steam rather than roast, and steamed vegetables in the oven are grey and sad.

Charring. Very hot pan or grill, minimal movement, letting one side blacken slightly. Adds bitterness and depth that balances sweetness.

Braising. Long slow cooking with liquid and fat, for sturdy greens. Southern-style collards, Italian cavolo nero cooked down for an hour. Not fresh and bright — soft, savoury and completely different.

Both fast and slow work. It is the middle — twenty minutes of boiling — that produces the grey mush people remember.

The seasoning

Greens need more than people give them.

Salt. In the blanching water, and again in the pan.

Fat. Greens are not satisfying without it. Olive oil, and plenty.

Acid. Lemon or vinegar at the end. This is the element most often missing and it transforms them.

Chilli and garlic, which is the standard combination for a reason.

Something savoury. Soy sauce, miso, olives, capers, nutritional yeast, toasted nuts.

Bitterness

Bitterness in greens is not a fault. It is a flavour, and the traditions that use bitter greens most have techniques for balancing rather than removing it.

Fat softens bitterness. Olive oil, tahini, nuts.

Salt suppresses bitterness perception measurably.

Acid balances it.

Sweetness, from a little sugar, from raisins, from caramelised onions.

Blanching removes some of the bitter compounds into the water.

The classic combination of bitter greens with garlic, chilli, olive oil, lemon and raisins or pine nuts covers all of these at once, which is presumably why it appears across the Mediterranean.

Bitterness perception is also genetically variable. Some people are markedly more sensitive, which is a real difference rather than fussiness, and those people need more of the balancing elements.

Kale specifically

Remove the stems from mature kale, which are woody. Young kale can be used whole.

For raw kale in salads, massage it — with oil and salt, for a minute, until it darkens and softens. This genuinely changes the texture and makes it edible raw.

For cooked, sauté with a splash of water and a lid, then finish uncovered.

For crisps, tear into pieces, dry thoroughly, toss in oil, and bake at moderate heat until crisp — high heat burns the edges before the centres dry.

The nutrition point

Some vitamins are lost in cooking, particularly water-soluble ones into boiling water. Cooking also increases the availability of some compounds and reduces oxalate content, which affects mineral absorption.

The practical conclusion: eat them both ways, use the cooking liquid where possible, and do not let concern about nutrient loss stop you from cooking vegetables in a way you will actually eat.

A well-cooked green vegetable you enjoy is nutritionally superior to a raw one you do not eat.

The frozen option

Frozen spinach, peas and edamame are excellent, cheap and always available.

Frozen spinach in particular is more practical than fresh for cooking, since fresh spinach reduces to almost nothing and frozen is already concentrated.

Squeeze the water out of thawed frozen spinach thoroughly before using it, which is the step that most often gets skipped and which is why spinach dishes go watery.