Heat half of the oil in a large wok or frying pan over a high heat. Add the chicken and cook for 5-6 mins until browned all over. It doesn’t need to be cooked through at this point. Remove to a plate using a slotted spoon and set aside.

Pour the remaining oil into the pan and set over a medium heat. Stir in the onion and fry for 2-3 mins, then stir in the garlic and chillies. Cook for a further 7-9 mins until the onions are softened and translucent. Return the chicken to the pan, along with the tamarind paste, garam masala and chaat masala. Season and stir well to coat. Cover and cook for 5 mins, or until the chicken is cooked through.

Remove from the heat and leave to cool for 2 mins before stirring in the tomato and cucumber. Garnish with the coriander and spring onion, and serve with lemon wedges on the side for squeezing over.