Heat the oil in a large frying pan over a medium heat. Fry the onion with a good pinch of salt for around 5 mins until beginning to soften. Add the garlic and ginger and fry for 2 mins. Stir in the curry powder and turmeric and stir-fry for a further minute or so. Tip the chicken into the pan, coating in the spicy onion mixture and cook for 3-4 mins until sealed.

Pour the coconut milk and 200ml water into the pan along with the peanut butter, sriracha, fish sauce and sugar. Stir to combine. Remove any woody outer leaves of the lemongrass and bash with the end of a rolling pin. Cut in half and place in the curry. Bring to a simmer and cook for 10 mins until the sauce has thickened and the chicken is cooked.

Add the green beans and red pepper and simmer for another 4-5 mins until just cooked. Taste and add any extra sugar, fish sauce or salt as necessary. Remove the lemongrass before serving.

Stir through most of the peanuts, then top with coriander and the remaining peanuts. Serve with rice and lime wedges on the side for squeezing over.