In a mixing bowl, combine Greek yogurt, lemon juice, ginger-garlic paste, turmeric, garam masala, ground cumin, coriander, smoked paprika, chili powder, salt, and oil into a flavorful marinade.

Cut the chicken into bite-sized chunks, coat with the marinade, cover, and refrigerate for at least 1 hour.

Heat a grill pan or skillet over medium-high heat and sear the marinated chicken pieces for 4-5 minutes per side.

Remove the cooked chicken and set aside.

In the same skillet, lower the heat and sauté butter and oil, then add onions until golden brown.

Stir in minced garlic and ginger, then add ground spices and toast for 30 seconds.

Mix in tomato paste and crushed tomatoes, simmering for about 10 minutes.

Reduce heat and stir in heavy cream or coconut milk, then add grilled chicken back into the skillet, simmer for 5 minutes.

Finish with lemon juice and garnish with cilantro before serving.