Par boil the potatoes in a large saucepan of boiling water for 10 minutes. Drain well and set aside.
Heat the oil in a large frying pan and fry the cumin seeds for about 2 minutes, until they begin to splutter. Add the green chill seededi and fry for a further 1 minute.
Add the cauliflower florets and fry, stirring, for 5 minutes. Add the potatoes, the powdered spices and salt and cook for 7-10 minutes, until the vegetable are tender.
Garnish the aloo gobi with coriander and Lemon wedges.