Method:

1. Prep all your ingredients before starting to cook. Once things are hot you don't want to be flustering about!
2. Heat the ghee in a large pan. Once it's hot add the whole fennel, cumin, fenugreek and mustard seeds. Let them sizzle for a few seconds (don't burn!) then add the ginger.
3. Once the ginger has cooked out for about 30 seconds, add the onions, chillies and curry leaves. Cook for a few minutes, stirring occasionally until the onion is browned. This takes a little while, but it's worth it!
4. Next, add the tomatoes, and cook down a bit, until it turns a deeper red colour.
5. Add the ground spices. Cook down, stirring often, until the oil starts to leave the sides of the pan. This indicates that the spices have released their aromatic oils. i.e. delicious flavour. Do add a splash of boiling water if it starts to burn: Burnt spices = bitter.
6. At this point, you should have a very enticing smelling paste in the pan. Add the tamarind paste, fish broth and 500ml of water to start with. Stir, bring to a boil, and reduce the heat. Taste for seasoning, sweetness and sourness, adding salt, lime juice and sugar as required.
7. Once you've perfected your sauce, blend it (a handheld blender is a timesaver here). Add water until it reaches the desired consistency. My preference is quite thick and creamy. Taste again for seasoning.
8. Now is the time you might choose to set aside some of the sauce for future curry endeavours (fish, peeled boiled eggs or chicken are delicious). If you're cooking this in advance for friends, keep the sauce on a low heat and add the fish when your guests are ready to eat.
9. Place the salmon into the hot sauce, and leave to poach gently - don't let it boil. A few short minutes later, when the salmon flakes easily, it's ready.
10. To serve, swirl through some cream and sprinkle on coriander leaves. Serve with rice.