Marinate the chicken pieces with ingredients specified and set it aside for 30 mins.
Slice the onions. Fry on medium heat in 1.5 tbsp oil for around 8-10 mins till light brown in color, add the cashew nuts. Fry on medium heat for another 1-2 mins. The onions should not become too dark in colour. Set aside, cool and grind it to a paste by adding around 2-3 tbsp water.
Dry roast the Kasuri Methi (Fenugreek Leaves) and crush it with your hands when cooled.
Fry Chicken
To fry the chicken pieces, heat 2 tbsp oil in a large frying pan and place the marinated chicken pieces side by side without the extra marinade. Fry on high to medium high heat for 3 mins and then flip the pieces. Continue to fry on high to medium high heat on this side for 3 mins. Fry for another 2 mins on medium heat on each side till uniformly browned.
Make Gravy
Heat oil in a pan and add the ginger garlic paste.
Fry on low heat for 2 mins and then add the tomato purée.
Give a mix for a minute and then add the Onion-Cashew Paste.
Mix and fry on medium heat for 4-5 mins till oil separates.
Add all the Spice Powders and 1/2 tsp salt and cook on medium heat for 3-4 mins till oil separates.
Now switch off heat and add the room temperature milk (boiled and cooled) and give a mix. Switch on heat.
Keep stirring for 3-4 mins on low to medium low heat till it's cooked and oil separates.
Now add the fried chicken pieces and mix it well.
Keep mixing and frying the chicken pieces on medium heat for 3-4 mins till oil separates.
Now add 250 ml water, give a mix and cover and cook on low heat for 15 mins till meat is cooked and oil separates.
Now add the cream, chaat masala and dry roasted Kasuri Methi. Mix and cook on low heat for 2-3 mins. Serve with roti, naan or rice.