Ingredient

Ratatouille

Ratatouille is a Provençal dish of aubergine, courgette, peppers, onions and tomatoes. The one rule that decides whether it is good is counter-intuitive and widely ignored: the vegetables are cooked separately and combined at the end. Everything thrown into one pan produces a watery, uniform, slightly grey stew.

Why separately

Each of these vegetables wants something different, and putting them in one pan means all of them get the wrong thing.

Aubergine is a sponge that needs high heat and enough fat to collapse into silkiness. Courgette is mostly water and goes from firm to mush in a couple of minutes. Peppers need long, gentle cooking to sweeten. Onions need time to soften without colouring. Tomatoes need to be reduced.

Cook them together and the courgette is destroyed before the pepper has softened, the aubergine steams instead of browning because everything else is releasing water into the pan, and nothing has been allowed to concentrate. The result tastes of dilution.

Cooked apart, each one is browned and concentrated in its own right. Combined at the end and warmed through together for a short while, the flavours marry while the textures stay distinct. It is more washing up and it is the whole difference.

The method

One pan, used repeatedly, is fine — you do not need five.

1. Cut everything into pieces of roughly the same size, generous rather than small.
2. Fry the aubergine first, in a good amount of olive oil over a decent heat, until browned and soft. Lift it out. It will drink the oil; let it.
3. Fry the courgette hard and fast until coloured at the edges but still holding its shape. Lift it out.
4. Fry the peppers more gently, longer, until soft and sweet. Lift them out.
5. Soften the onions slowly in the same pan, then add garlic.
6. Add the tomatoes — fresh and skinned, or tinned — with thyme and a bay leaf, and cook them down until thick and no longer watery. This is the sauce and it must be reduced, not merely warmed.
7. Return everything to the pan, fold together gently, and cook for another ten to fifteen minutes so the flavours meet.
8. Take it off the heat and stir in torn basil and a good glug of raw olive oil. Season, and taste for acidity — a little vinegar often lifts it.
9. Serve warm or at room temperature rather than hot. It is better the next day.

The variations

Classic Provençal

Vegetables cooked separately, combined, stewed briefly. Rustic, chunky, olive-oil rich.

Confit byaldi

The Thomas Keller version made famous by the film — vegetables sliced into thin rounds, arranged overlapping in a spiral over a pepper and tomato base, and baked slowly under parchment. Beautiful, and a different dish in texture.

Tian

The broader Provençal name for vegetables arranged in a shallow dish and baked. Confit byaldi is essentially a very precise tian.

Piperade

The Basque relative — peppers, onions and tomato, no aubergine or courgette, often finished with egg.

Caponata

The Sicilian relative — aubergine-led, with celery, capers, olives and a sweet-sour vinegar and sugar dressing.

What none of them are

A pan of vegetables boiled together in tinned tomatoes.

What goes wrong

• Watery. Everything cooked together, or the tomatoes not reduced. Cook apart and reduce the tomato properly.
• Grey and uniform. Nothing was browned. Each vegetable needs real heat in its own turn.
• Greasy. Too much oil went in with the aubergine and never cooked out. Use high heat so the aubergine collapses quickly, or pre-cook it.
• Bland. Under-seasoned, and missing acidity. Salt generously, and finish with vinegar or lemon and raw olive oil.
• Mushy courgette. Cooked too long, or cooked with everything else.
• Served fridge-cold. It tastes of very little cold. Room temperature or warm.

Common questions