Marinate the chicken pieces in a bowl with salt, garlic powder, sweet paprika, curry powder, and Greek yogurt until fully coated.

In a large skillet over medium heat, add vegetable oil and half of the butter. Sauté minced garlic and diced onion until fragrant and translucent.

Add the marinated chicken to the skillet and cook until browned on all sides but not fully cooked through.

Stir in tomato sauce, sugar, salt, black pepper, heavy cream, cayenne pepper (if using), garam masala, and additional curry powder. Bring to a gentle simmer.

Reduce heat and let the butter chicken simmer for about 15 minutes or until chicken is fully cooked through and tender.

Serve the butter chicken over steamed rice or alongside warm naan bread, garnished with freshly chopped parsley if desired.