1. Heat 2 tbsp of the oil in a large frying pan over medium-high heat. In batches, add the chicken and cook, stirring occasionally, for about 5 minutes, until browned. Transfer to a plate.

2. Add the remaining 2 tbsp oil to the pan and reduce the heat to medium. Add the onions and garlic and cook, stirring often, about 5 minutes, until golden. Add the coriander, cumin, turmeric, chili powder, cardamom, and ginger and reduce the heat to low. Cook, stirring often, about 2 minutes, or until the spices are fragrant.

3. Mix the yogurt and cornstarch together, then stir into the pan. Stir in the remaining stock. Bring to a boil, stirring constantly. Return the chicken to the pan and simmer, stirring occasionally, for 15 minutes, or until the chicken is opaque.

4. Stir in the cream and lemon juice and simmer for 5 minutes more. Serve hot.