Mustard oil has lots of character so the dish does benefit from its use, but if you don't have any to hand the recipe will still work with vegetable oil.
In a large wok or non-stick saucepan, heat the oil until it is smoking (NB - Do not leave hot oil unattended). Remove the pan from the heat and allow the oil to cool for ten seconds. Return the pan to the hob, turn the heat down and fry the asafoetida and mustard and nigella seeds for 30 seconds. Add the chillies, lentils and peanuts and fry for a further minute or until the lentils have started to colour.
Once cooked, stir in the curry leaves, cabbage and salt, to taste. Stir-fry for ten minutes making sure that the cabbage retains some firmness.
To serve, distribute the cabbage between 2-3 serving plates.
