Fish curry with coriander and lime

I put together this curry from spices I had in the cupboard. Other combinations and proportions might have worked better; but I was pleased with the zing and pungency of this version. Spring onions, mustard seeds, lime juice, and coriander were the key ingredients, I feel. Fresh chillis would have been a good addition. For 2.

Sunflower oil, for frying
1 onion, peeled and chopped
1 garlic clove, peeled and chopped
2tsp cumin seeds
1tsp coriander seeds
1tsp fenugreek seeds
1tsp mustard seeds
6 cardamom pods
6 spring onions, chopped
2 fillets of white fish, such as cod, coley, or hake
1tsp turmeric
Cayenne pepper, to taste
Salt, to taste
100ml water
Large bunch of coriander, washed and chopped
Juice of 1/2 half a lime

Warm about 2 tbsps of sunflower oil in a heavy pan, throw in the onion and garlic, and soften over a gentle heat. Add more oil if the vegetables threaten to catch.

In a dry saucepan, warm the cumin, coriander, fenugreek, and mustard seeds over a gentle heat, until they give off a toasted aroma. Grind them with the cardamom pods in a mortar. Add the spice mixture with the spring onions to the softened onions, and cook, stirring, for about two minutes.

Cut the fish into fork-sized pieces, and add them to the pan with the turmeric, cayenne, salt, and water. Bring to a simmer, cover, and cook gently for five to 10 minutes, or until the fish is white and flaky.

Take off the heat, and stir in the coriander and lime juice.