Mix the tandoori paste and yogurt together in a large bowl. Finely chop half of the coriander and stir this through, then add the chicken and toss to coat. Cover and set aside. Will keep chilled for up to a day.

Heat the oil and butter in a medium saucepan over a medium heat and fry the onion for 5-8 mins until soft and golden. Add the rice, then stir in the cardamom, cinnamon and turmeric, and season with salt.

Pour over the chicken stock, scatter over the green beans and bring to the boil. Cover with a lid, then reduce the heat to low and cook for 10 mins.

Meanwhile, line the chicken thighs up on a board with the longer sides against each other, tucking each thigh into a neat oblong shape. Push two long metal skewers parallel through the line of fillets so they are held together and make one large kebab. (If you don’t have long skewers, you can use shorter ones and make two separate kebabs.)

Heat the grill to high and grill the kebab for 20 mins, turning occasionally to make sure it browns evenly. (Or, do this in a hot griddle pan.) Check that the chicken is cooked through by looking at the spaces where the thighs rest against each other – if it's still raw, continue to cook, checking every few minutes, then push a knife into the fattest part to ensure the juices run clear. Spoon the biryani onto a serving platter and top with the kebab. Chop the remaining coriander and scatter this over, then serve with the lemon cheeks for squeezing over.