Mix everything together and marinate for at least 10 minutes (overnight is even better).
Heat 2 tbsp oil in a pan and cook the marinated chicken over medium-high heat for 10–12 minutes, until lightly charred and cooked through. Remove and set aside.
In the same pan, add 2 tbsp oil and 3 tbsp butter. Once the butter has melted, add the onions and sauté for 4-5 minutes.
Add the chopped garlic and cook for 1 minute.
Stir in the tomatoes, tomato paste, cashews, salt, cumin, coriander, paprika and Kashmiri chilli powder. Cook for 5–10 minutes until the tomatoes soften.
Add a splash of water, then blend the mixture until smooth. For an extra silky sauce, pass it through a sieve.
Return the sauce to the pan, add the cooked chicken, kasuri methi, sugar and double cream. Simmer on low heat for 10 minutes.
Finish with fresh coriander and a drizzle of cream.
