Marinate chicken: Mix chicken with yogurt, ginger-garlic paste, garam masala, paprika, turmeric, chili powder, and salt. Refrigerate 30–60 minutes.
Cook chicken: Grill or pan-sear chicken until cooked through, about 5–6 minutes per side.
Make sauce: In a saucepan, heat oil, cook onion until golden, add tomatoes and cook until soft. Stir in coconut milk and simmer 5 minutes.
Combine: Add chicken to sauce and simmer 2–3 minutes.
Garnish and serve: Sprinkle with cilantro and serve with rice or gluten-free naa