Here's a recipe I use
1 tsp chili powder
1.5 teaspoons of coriander/cumin powder
0.5 teaspoon turmeric
1 tablespoon tomato purée
125ml water.
4 tbsp sunflower oil
6 fresh curry leaves
0.5 teaspoon black mustard seeds
10 garlic cloves, peeled and crushed
salt
2 green chilies, cut in half (either leave in seeds if you like HOT or remove)
1 tablespoon lemon juice
15g chopped coriander leaves (?cilantro in USA)
5 -6 large potatoes, cut into pieces, but not peeled, cooked until JUST tender
Mix together the chilli powder, coriander and cumin powder, turmeric and tomato puree with a tablespoon of water to make a paste.
Heat the oil in a large frying pan or wok. Drop in a curry leaf. It should sizzle and immediately turn dark, then add the remaining curry leaves and mustard seeds. Once the mustard seeds start to pop, add the garlic, the paste and 125ml water. Cook, stirring, over a very high heat. Add the potatoes, salt and green chillies. Cook for 2 minutes. Mix in lemon juice. Serve with fresh coriander (cilantro) leaves.