In a medium bowl, combine Greek yogurt, lemon juice, ginger-garlic paste, turmeric powder, garam masala, ground cumin, coriander, smoked paprika, chili powder, salt, and a splash of oil. Mix well until smooth.

Coat the chicken pieces evenly in the marinade, ensuring each piece is thoroughly covered. Cover the bowl with plastic wrap and refrigerate for at least 1 hour, ideally overnight.

Heat a grill pan or skillet over medium-high heat. Once heated, add a drizzle of oil. Place the marinated chicken in the pan, avoiding overcrowding, and sear for 4–5 minutes on each side until cooked through.

Remove the chicken and set aside. In the same pan, reduce heat to medium. Add butter and oil, letting it melt. Add finely chopped onions and sauté until golden, about 5–7 minutes.

Add minced garlic and ginger, stirring for about 1-2 minutes until fragrant. Then, stir in turmeric, garam masala, smoked paprika, cumin, and chili powder. Allow them to toast for about a minute.

Next, stir in tomato paste and crushed tomatoes, mix well, and let simmer on medium-low heat for 10-15 minutes until thickened.

After thickening, stir in heavy cream or coconut milk, season with salt or sugar if desired, and let it simmer gently for another 5 minutes.

Add the grilled chicken back to the sauce, gently stirring to coat. Let it simmer for an additional 4-5 minutes. Finish with fresh lemon juice and chopped cilantro.

Serve the Chicken Tikka Masala with hot basmati rice, naan, or roti.