Heat the oil in a heavy-bottomed saucepan
over medium-high heat. When hot, add the cumin. As soon as the seeds begin to pop, stir in the tomato puree
and cook for 30 seconds. Stir in the potatoes
and 1 1/2 teaspoons of the salt, reduce the heat to low and cook, covered, until the outer layer of the potato is cooked, 8 to 10 minutes. Add the cauliflower, ginger
, coriander, turmeric
, cayenne and the remaining 1 1/2 teaspoons salt and stir it all together without damaging the florets. Cover and cook until the cauliflower
is tender, 15 to 20 minutes, adding 1/2 cup of the cilantro during the final minutes of cooking. Serve garnished with the remaining 1/2 cup cilantro.