Vegetables you actually want to eat: roasting, blanching and caramelising

Boiling in water washes flavour, sugars and some vitamins out of vegetables, and the temperature never rises above 100 °C. The taste stays flat and the texture soft.

With dry heat — in the oven, in a pan, on the grill — the surface reaches 150 °C and more. Natural sugars caramelise, proteins and sugars undergo the Maillard reaction, and hundreds of new aroma compounds appear. The same carrot or broccoli becomes sweet, nutty and intense after roasting.

Cut pieces to the same size — 2–3 cm. If you're roasting different vegetables on one tray, add them in stages or cut the hard ones smaller and the soft ones larger.

Blanching is brief cooking in boiling salted water followed by an immediate plunge into iced water. Vegetables become tender but stay crisp, and green ones turn bright emerald.

Use plenty of water so it doesn't stop boiling when the vegetables go in. Salt generously — 1 tbsp per 2 litres. As soon as they're done, move them to a bowl of iced water for 1–2 minutes: it stops the cooking instantly and sets the colour.

The rules are the same as for meat: a well-heated pan, small batches, no constant stirring. Leave the vegetables alone for 2–3 minutes to form a crust, and only then toss.

Mushrooms are a special case. At first they release a lot of water and it looks like a mistake. Don't salt or cover them: let the water boil off over high heat, and only then will the mushrooms start to brown. Salt at the very end — salt draws out moisture and stops a crust forming.

Courgettes are 95% water. For fritters, bakes and fillings, grate the courgette, salt it (½ tsp per 500 g), leave for 15–20 minutes and squeeze hard by hand or through muslin — up to a third of the weight comes out. For frying in rounds, use high heat, a single layer and no lid.

Modern aubergine varieties are hardly bitter. But salting still helps: slices sprinkled with salt for 20–30 minutes lose excess moisture, firm up and absorb far less oil when fried. Rinse and dry after salting.

Real caramelised onions — jammy, soft and deep gold — take time: 40–60 minutes over low heat. "Caramelised onions in 10 minutes" are just fried onions.

Thinly slice 1 kg onions. Melt 30 g butter with 1 tbsp oil in a wide heavy-based pan. Add the onions and a pinch of salt and cover for the first 10 minutes to soften them. Then take off the lid and cook over low heat, stirring every 5–7 minutes. If they start to stick, add a spoonful of water and scrape the bottom — that's the caramel.

Water-soluble vitamins (C and the B group) leach into water and break down with long heating. Fat-soluble ones (A, E, K) and carotenoids, on the other hand, are better absorbed with fat and after cooking.

Frozen vegetables are often just as nutritious as "fresh" ones from the shop: they're frozen within hours of picking, at peak ripeness, while fresh ones in winter may spend weeks in transit and on the shelf, losing vitamins.

Don't thaw them before cooking — they go limp. Add them straight from the freezer to soups and stews. To roast, spread them on a hot tray in a single layer, drizzle with oil and add 5–10 minutes. To fry, use high heat and small batches so the ice evaporates fast.