Marinate the Chicken: In a bowl, combine chicken pieces with salt, garlic powder, paprika, curry powder, and Greek yogurt. Stir well to coat. Cover and refrigerate for at least 30 minutes—or up to overnight for deeper flavor.

Start the Sauce Base: In a large skillet or Dutch oven, heat the vegetable oil over medium heat. Add 1 tablespoon of butter. Once melted, stir in the minced garlic and diced onion. Sauté until the onion becomes soft and translucent, about 5–7 minutes.

Build the Tomato Sauce: Add the tomato sauce, sugar, salt, and black pepper. Stir to combine and bring the mixture to a gentle simmer.

Cook the Chicken: Push the sauce to the side and add the remaining 2 tablespoons of butter to melt. Add the marinated chicken to the pan. Stir to coat each piece in the tomato sauce, then simmer on medium-low heat until the chicken is cooked through, about 15 minutes.

Enrich the Sauce: Pour in the heavy cream, stir to combine, and allow the sauce to simmer and thicken—about 5 minutes. Watch carefully to avoid boiling.

Add Final Seasonings: Stir in garam masala, additional curry powder (if desired), and cayenne pepper for heat. Adjust salt and sugar to taste.

Garnish and Serve: Sprinkle chopped parsley over the dish before serving. Serve hot with warm naan or steamed rice to soak up the sumptuous sauce.