Use your discretion with the cayenne. Add more if you like things spicy, or scale it back to a pinch if you're scared.
2 to 3 medium potatoes
1 medium cauliflower
3 Tbsp. canola oil
1 onion, chopped
1 tsp. cumin seeds
1 1/2 tsp. ground cumin
1/2 tsp. ground coriander
1/2 tsp. ground turmeric
1/8 tsp. ground cayenne
1 tsp. salt
Black pepper
Boil the potatoes in their jackets until tender when pierced with a knife. Cut the cauliflower into florets about 1½-inches wide. Soak them in a bowl of water for 30 minutes. Drain.
Peel the potatoes and cut them into ¾-inch dice. In a large, non-stick frying pan, heat the oil over medium heat. Fry the onion until translucent, stirring occasionally, 4 to 5 minutes. Stir in the cumin seeds and sauté for about a minute. Add the cauliflower and stir until it starts to brown in spots, about 5 minutes. Cover, turn the heat to low, and simmer until cauliflower is almost done, but still has a bit of crispness (8 to 12 minutes). Add the diced potatoes and the rest of the spices, and gently stir. Cook uncovered over low heat until potatoes are heated through, about 5 minutes more.
Source: Adapted from Illustrated Indian Cookery by Madhur Jaffrey