First of all cut the chicken into medium bite-size pieces. Marinate the chicken with the ingredients from the chicken marinade list. Mix well to coat the each chicken pieces evenly. Set aside and marinate for 15 minutes. ( If you have time, you can marinate for longer. )
In the meantime, finely chop the shallots, garlic cloves and coriander.
Heat the grill pan/skillet over medium-high heat, drizzle 1 tablespoon of oil and grill the marinated chicken pieces 1-2 minutes until it gets the nice golden colour, then turn sides and cook for another 1-2 minutes. Remove from pan and set aside.
To cook the butter sauce, add 3 tablespoon of unsalted butter in the pan, fry the chopped shallots with medium heat until brown. Then add the garlic paste, onion paste and stir fry few seconds.
Follow with the tomato puree, turmeric, paprika, garam masala and salt to taste. Stir for few seconds.
Pour the water, cream and cashew nut paste in and cook for another 1 minute.
Place the cooked chicken back in and stir well to combine with the sauce. Add more water if needed.
Close the lid and cook for another 2-3 minutes. Sprinkle the dried fenugreek leaves and chopped coriander.
Remove from heat and transfer to serving plate.
Serve with cooked basmati rice, naan or flat bread. Enjoy!