If using frozen vegetables, thaw them as per packet instructions.
Heat oil in a heavy-duty pan. Once the oil is hot, add grated ginger, cumin and nigella seeds. Saute ginger for 30 - 40 seconds. You can smell the aroma of roasted ginger.
Now add chopped onion. Saute the onion for 3 - 5 minutes or till they turn translucent and light brown. Keep stirring the onion at regular intervals, else they might burn and turn black.
Add tomato puree, salt, spices, and cook the masala for 2 - 3 minutes.
Add cauliflower florets, potatoes, and coconut milk. Stir to coat each piece of the vegetable with the masala.
Add 1 Cup of water or lukewarm vegetable stock. Add green peas. Stir. Cover the pan with the lid for the vegetables to cook till fork tender. After 15 minutes, open the lid and give the curry a nice stir. Check for doneness if still cauliflower/potato not cooked through, put the lid back on and cook for some more time until fork tender.
Garnish gobi curry with chopped cilantro or parsley.
Serve Cauliflower Curry with jeera rice or chapati.