Step 1

Heat oil in a large pan over medium heat. Add garlic, ginger, lemongrass and white spring onion, then cook, stirring, for 1-2 minutes until fragrant. Add sambal oelek, sugar and kaffir lime leaves, and cook, stirring, for 1 minute, then add lime juice, fish sauce, stock and 3 cups (750ml) water. Bring to a simmer and cook for 4-5 minutes until flavours have infused. Add tomatoes and prawns, and cook for 3-4 minutes until prawns are just cooked.

Step 2

Meanwhile, cook noodles according to packet instructions. Drain and set aside.

Step 3

Divide noodles among bowls, ladle over soup and top with coriander leaves and remaining spring onion to serve.