Mix together yogurt, coriander powder, cumin powder, garam masala, turmeric and red chili powder in a bowl. Cut the chicken thighs into small pieces and add to the above mixture. Cover and let it marinate in the fridge overnight.
Melt butter in a pan, roast onion till translucent. Transfer the onions in a food processor and grind with tomato puree and cashews to get a paste.
In a heavy bottom pan melt butter, add ginger garlic paste, onion and tomato paste. Stir well and cook for 5 to 7 minutes till oil starts separating.
Add marinated chicken, coriander powder and garam masala. Stir and coat the chicken pieces. Cook until the gravy thickens and chicken is soft and tender
Season with salt. Cover and cook for another 10 min to let the flavor come together. Garnish with fresh coriander.
Once cool shred the chicken with fork and mix.