In a medium bowl, combine chicken, salt, garlic powder, sweet paprika, curry powder, and Greek yogurt. Mix well, ensuring the chicken is evenly coated. Let it marinate for at least 15 minutes while preparing the other ingredients.

Heat 3 tablespoons of oil in a large skillet over medium-high heat. Add the marinated chicken and cook for about 8-10 minutes, stirring occasionally, until golden brown and cooked through. Remove the chicken from the skillet and set aside, leaving the oil in the pan.

Reduce the heat to medium and add 1 tablespoon of butter to the skillet. Deglaze the pan by scraping any browned bits, adding a splash of water if needed. Add the minced garlic and diced onion, along with a pinch of salt. Sauté until the onion is translucent and fragrant.

Stir in the tomato sauce and sugar. Let it simmer for 2-3 minutes before adding the chicken back into the skillet. Mix well, then pour in the heavy cream. Stir until the sauce turns a beautiful orange hue.

Add cayenne pepper (if using), garam masala, curry powder, and black pepper. Let the sauce simmer on low heat for 10 minutes, allowing the flavors to meld. Add in the rest of the spices & salt to taste.

Stir in the remaining 2 tablespoons of cold butter and let it melt into the sauce for a silky finish. Sprinkle with chopped parsley if desired.

Serve hot with naan bread and steamed rice. Enjoy the creamy, flavorful goodness!