Large tomato

Use the same weight of ordinary tomatoes, chopped. Taste for acidity; add a pinch of sugar if they are very sour.

Use the same weight, draining some juice if the curry should be thick. Simmer 5–10 minutes longer to reduce the extra liquid.

Use about 30% of the weight, dilute with water to roughly the original volume and add early. It gives a deeper colour and stronger acidity; adjust salt and sugar.