This is a big mamma of a curry, and it's good!
2 Tbsp butter
700g all-purpose or waxy potatoes, peeled and cubed
½ cup vegetable oil
1 tsp black mustard seeds
1 onion, peeled and finely chopped
1 tsp lemon juice
1 tsp ground coriander
1 tsp ground cumin
¾ tsp ground turmeric
½ tsp cayenne pepper
½ tsp sweet ground paprika
2 tomatoes, peeled and diced
2 Tbsp chopped fresh coriander (cilantro)
1 Tbsp grated fresh ginger
1 tsp salt, or more to taste
1 medium-sized cauliflower, washed and broken into florets
1 Melt the butter in a large frying pan (skillet). Add the potatoes and fry until they are tender and browned. Transfer potatoes to a plate. Wipe out pan and add vegetable oil. When it is nice and hot, but before it starts smoking, add the mustard seeds. Cover pan with a lid or splatter screen and shake pan from time to pop until the mustard seeds have finished ‘popping’.
2 Slip in the onion and brown it lightly. Reduce the heat and add the lemon juice, ground coriander, cumin, turmeric, cayenne pepper and paprika. Blend well, then add the tomatoes, fresh coriander, ginger and salt; if the mixture seems a little dry, add 2-3 tablespoons of water.
3 Add the cauliflower and potatoes – the pan will be full! Turn everything carefully with a large spoon until coated with the spicy mixture. Reduce the heat and cover pan tightly. Cook for about 15 minutes, or until cauliflower is well impregnated with the spice mixture and cooked to your liking; stir occasionally (traditionally the cauliflower is cooked until very tender, but you can halt the cooking earlier if you wish to keep the cauliflower firmer). Transfer to a serving dish and serve hot or warm.