In a large wok or nonstick saucepan, heat the oil until it is smoking. 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 burner, and turn the heat down and fry the asafetida, mustard seeds, and nigella seeds for 30 seconds. Add the chiles, lentils, and peanuts and fry for another minute, or until the lentils have started to color.
Once cooked, stir in the curry leaves, shredded cabbage, and salt, to taste. Stir-fry for 10 minutes making sure that the cabbage retains some firmness.
To serve, divide the cabbage between 2 or among 3 serving plates.
*Can be found in specialty Asian markets Mustard oil has lots of character so the dish does benefit from its use, but if you don't have any on hand, the recipe will still work with vegetable oil.