Rasam is an everyday dish in southern India. It’s a sweet and sour soup-like concoction with myriad incarnations but commonly has flavours of tamarind, tomato, black pepper and curry leaf predominating. Pretty much all cookbooks dealing with the cuisine of south India will have one or more recipes for Rasam and, by way of example, I have listed a few in the References.
Lentils or other pulses would typically feature, but I was inspired to create a soup-base capturing these flavours as a foundation for a fish soup. This was more than 10 years ago and I have been making my creation, largely without alteration, ever since, as it is such a simple, spicy, zingy, big-hitter.
And it's a great way to enjoy some of the cheaper fish varieties that are available at this time of the year. Species such as whiting, dab, flounder and pollack. But my favourite for this particular dish is plaice. Its texture, after a minute or so's poaching, is absolutely perfect for the final result. I once tried scallop as the feature ingredient but I knew as soon as I served it that this was a fruitless effort - the punch of the soup-base had no room for accommodation.
This is very easy to serve as a dinner-party starter as the soup-base only takes about half an hour to make and can be done a day or so ahead of time. Finishing the dish off only takes about 5 minutes.
As mentioned above, the flavour of tomato is key in this recipe. More than once I have thought about using tinned tomatoes - I'm a very big fan of them. But each time I have failed to convince myself they’re the right thing here. Everything needs to be bright and zingy and I even think that slightly underripe tomatoes are perfectly in order here, and they are the quite opposite creatures to the ones that come out of the tin. Tinned tomatoes would also have the effect of over-thickening the soup-base, which is not the desired texture.
The only trick in this particular dish is trying to achieve the right balance of sweet and sour. But this, in itself, is a matter of personal preference. The flavour you’ll get from freshly made tamarind purée, whether from fresh or dried tamarind, will always have a fruity blend of sweetness and sourness. Bought ready-prepared products vary wildly in their flavours. This isn’t necessarily a problem because if in doubt you just add less than you think to start with and then adjust with more tamarind purée and/or a pinch or two of sugar. It’s totally to your taste. But keep in mind there is a squeeze or two of lime to go in at the end of the recipe, so a final adjustment of sourness is there to be had.
Rasam Fish Soup
Ingredients (serves 2)
1 tbsp sunflower or vegetable oil
2-3 cloves
10-12 curry leaves
1½” piece of ginger, coarsely chopped
¼ tsp turmeric
¼ tsp chilli powder
50ml white wine
3 tomatoes (350g), coarsely chopped
500ml fish stock
1 tsp tamarind puree (or more, to taste)
⅓ tsp cumin seeds
⅓ tsp black peppercorns
A pinch or so of caster sugar (to taste)
150g plaice fillet, skinned and cut into 1” pieces (or alternative fish, see recipe intro)
1 spring onion, finely sliced
1 green chilli, deseeded and finely sliced
1-2 tbsp fresh coriander, coarsely chopped
Lime juice, to taste
Method
In a saucepan, heat the oil to medium hot then sizzle the cloves and the curry leaves until the cloves have swollen and are releasing their aroma. Add the chopped ginger and sweat gently for a couple of minutes without colouring. Next fry the turmeric and chilli powder for a few seconds but be careful not to let them burn. Add the white wine and allow to boil down for a minute or so, then add the chopped tomatoes, the fish stock and the tamarind purée. Bring to the boil and simmer over a medium heat, stirring regularly, for about 10-15 minutes until the tomatoes have broken down. Allow to cool, then press everything through a sieve into a bowl using the back of a ladle. The soup-base (which should now be still about 450-500ml) is now ready and can be kept in the fridge for a day or so until ready to use.
Coarsely grind the cumin seeds and black peppercorns using a pestle and mortar. Return the soup-base to a saucepan pan along with these ground spices and bring back to the boil. Test the flavour for your preference of sweet/sour and adjust accordingly with tamarind puree and/or some caster sugar.
Add the fish pieces and, over a fairly low heat, allow them to poach for about 1 minute. Stir in half of the sliced spring onion, green chilli and fresh coriander and then ladle into bowls. Drizzle in a little lime juice (to taste) and garnish with the remaining sliced spring onion, green chilli and fresh coriander.
References
"Dakshin: Vegetarian Cuisine from South India", Chandra Padmanabhan (1992), pp. 11: https://www.amazon.co.uk/Dakshin-Vegetarian-Cuisine-South-India/dp/9625935274
"The Indian Kitchen", Monisha Bharadwaj (1996), pp. 89: https://www.amazon.co.uk/Indian-Kitchen-Monisha-Bharadwaj/dp/1856266591
"The Dal Cookbook", Krishna Dutta (2013), pp. 48: https://www.amazon.co.uk/Dal-Cookbook-Krishna-Dutta/dp/1909166057