1. Heat the oil in a large saucepan over medium heat. Add the red curry paste and cook for about 1 minute until fragrant.
2. Pour in the stock, then add the lemongrass, ginger, garlic, kaffir lime leaves and chillies.
3. Bring to a gentle boil, reduce the heat and simmer uncovered for 10–12 minutes to allow all those aromatics to flavour the broth.
4. Add the mushrooms and tomato wedges and simmer for another 4–5 minutes, until the mushrooms are tender but still have a little bite.
5. Stir in the fish sauce, brown sugar and coconut milk.
6. Simmer gently for 2 minutes. Avoid aggressively boiling the soup once the coconut milk has been added.
7. Add the prawns and cook for 2–3 minutes, or just until they turn pink and opaque.
8. Don’t overcook them, the residual heat will continue cooking them slightly after the pot comes off the stove.
9. Remove the soup from the heat.
10. Stir through the lime juice and lime zest, then taste.
11. Tom yum should hit you with sour first, followed by salt, heat and just enough sweetness to round everything out. Add another splash of fish sauce, lime juice or pinch of sugar until it tastes right to you.
12. Remove the large pieces of lemongrass, ginger and lime leaf if you prefer a cleaner bowl.
13. Ladle into bowls and finish with coriander, spring onion, fresh chilli and a drizzle of chilli oil.
14. Serve immediately with extra lime wedges on the side.

Tayla’s Tip

The lime juice goes in after the soup comes off the heat. Boiling fresh lime juice can dull that sharp, fresh acidity that makes tom yum so addictive.

For an extra punchy broth, keep the prawn shells and simmer them in your stock for 10–15 minutes before starting the recipe, then strain. It’s a tiny extra step that gives the soup incredible depth.