Add the onion, three-quarters of the coriander, half the lime zest, the red chilli, two kaffir leaves, the ginger and garlic to a pestle and mortar and smash into a paste (or use a food processor).
Add the paste to a heated frying pan or wok with the oil and cook for 20- 30 seconds, then add the coconut milk, fish sauce, the remaining lime zest and two kaffir leaves, the lemongrass and sugar and bring to the boil, stirring regularly.
Meanwhile, add the rice with double the amount of water to a pan and bring to the boil. Once boiling, cook for three minutes, turn off the heat and put a lid on the pan so the rice can carry on steaming for seven to eight minutes. Do not stir as you want the rice to steam, absorb the water and fluff up.
Add the pepper, king prawns and sugar snap peas to the hot coconut milk and cook for two to three minutes until the prawns turn pink. Serve the rice and curry in separate bowls with a scattering of the remaining coriander and a final squeeze of lime.