Marinate the chicken pieces with ginger-garlic paste, salt, red chili powder, and turmeric powder. Let it marinate for at least 30 minutes.
Heat oil in a pan and sauté chopped onions until golden brown.
Add chopped green chilies and the marinated chicken. Cook until the chicken is browned.
Add tomato puree and cook until the raw smell disappears.
Mix in the cashew nut paste and cook for a few minutes.
Add sugar, vinegar, tomato ketchup, and a pinch of garam masala. Adjust the sweetness and acidity according to your taste.
Pour in the heavy cream and stir well. Simmer the curry until the chicken is fully cooked and the flavors are well combined.
Adjust the seasoning with salt and additional spices if needed.
Garnish with chopped coriander leaves before serving.