Recipe

Make Tamarind Paste

1. In small saucepan over high heat, bring water to a rolling boil. Break tamarind into small pieces and drop into boiling water. Boil for 3 to 4 minutes. Heat breaks down tamarind pulp and makes it easier to separate fibres. If using dried tamarind, it will start to expand. If using tamarind block, it will absorb water and start to soften.
2. Over large bowl, strain through fine-mesh sieve, pressing out every bit of liquid and paste. I recommend using large bowl to help minimize mess. Make sure to scrape paste off bottom of sieve and mix it into liquid. Discard pulp in sieve. Allow to cool before using. Store in airtight container in fridge for up to 1 week, or in freezer for up to 3 months.

Make Tom Yum Paste

1. In small food processor, pulse dried shrimp until they look stringy, almost like floss. Set aside.
2. In small saucepan over medium heat, heat 1 tbsp of sunflower oil. Add chilis and cook until chilis turn dark red and skin starts to plump up and looks smooth, 1 to 2 minutes. Transfer chilis to stone mortar and pestle. (Alternatively, you can use small food processor.)
3. Return pan to medium heat. Add remaining 1⁄4 cup of sunflower oil and heat for 1 minute. Add garlic and shallots and cook, stirring frequently, until cooked but not crispy, 2 to 3 minutes. Shallots will start to look transparent. Remove from heat.
4. Using slotted spoon, transfer garlic and shallots to mortar with chilis. Leave oil in pan. Pound garlic and shallots to fine paste. Add paprika and pound to mix.
5. Return pan to medium heat and allow sunflower oil to heat for 1 minute. Scoop paste out of mortar, add to oil and cook, stirring frequently, for about 2 minutes. Add shrimp floss, Tamarind Paste and coconut sugar. Reduce heat to medium-low and cook until sugar is fully dissolved, 1 to 2 minutes. Store in airtight container in fridge for up to 3 days.

Make Soup

1. In medium pot over high heat, bring water to a rolling boil. When water is boiling, reduce heat to medium and add lemongrass, galangal, garlic, shallots and lime leaves. Boil for 5 minutes. Stir in Tom Yum Paste and boil for another 5 minutes.
2. Without stirring, add shrimp, oyster mushrooms and tomatoes. Increase heat to high and cook, without stirring, for 2 to 3 minutes, or until shrimp are pink and opaque. Make sure to wait until shrimp have had a chance to cook before stirring.
3. Stir in Tamarind Paste and cane sugar, and cook for another minute. Stir in fish sauce and lime juice. Remove from heat. Stir in cilantro, green onions, sawtooth coriander and chilis. Ladle into bowls and serve.