Step One Put the mustard seeds in a clean spice or coffee grinder and grind to a fine powder. Empty into a small bowl. Add 175ml (6fl oz) water and set aside to soak for 20–30 minutes; do not stir.

Step Two Put vegetable oil, about 5cm (2in) deep, in a wok, deep frying pan or deep fryer and set over medium heat. When the oil is hot, put in the aubergines and deep-fry for about 8–10 minutes, until they are golden brown. Lift out with a slotted spoon and drain on kitchen paper. Turn the heat to medium–high to reheat the oil, then put in as many cauliflower florets as the pan will hold in a single layer. Fry until they are golden brown, about 2–3 minutes. Lift out with a slotted spoon and drain on kitchen paper. Fry all the florets. (The oil can be strained and re-used.)

Step Three Combine the turmeric, cayenne pepper and 2 tablespoons water in a small cup. Set this spice mixture aside.

Step Four Put the oil in a frying pan and set over medium heat. When very hot, put in the panchphoran. As soon as the mustard seeds in the panchphoran begin to pop – a matter of seconds – add the spice mixture. Stir once or twice. Carefully pour the watery top of the ground mustard seed mixture into the pan, making sure to leave all the thick paste behind (you do not need the thick paste). Add the aubergines, cauliflower, green chillies and salt. Stir to mix well. Bring to the boil. Cover, turn the heat to low and simmer for 3–4 minutes, or until there is only a small amount of liquid left at the bottom of the pan. Serve hot.