Heat oil in a pan. Add chopped onion and sauté until translucent.
Add ginger-garlic paste, then boneless chicken. Cook on low flame for 4 minutes.
Add all spices. Mix well.
Add vinegar and soy sauce. Stir.
Add blended tomatoes, cover, and cook for 5 minutes.
Add yogurt, mix well, and cook for 2 minutes.
Stir-fry capsicum and onion cubes on high flame and add to the chicken.
Cover and cook for 2 more minutes.
Garnish with green chillies and ginger.
Serving.
Serve hot with white rice or naan.