In a bowl, combine 1 teaspoon salt, garlic powder, sweet paprika, ½ teaspoon curry powder, and Greek yogurt. Add the chicken chunks, toss to coat thoroughly, and let rest for at least 15–30 minutes (or up to 2 hours in the fridge for deeper flavor).

Heat 2 tablespoons vegetable oil and 1 tablespoon butter in a large skillet over medium-high heat. Add the marinated chicken in a single layer and sear until golden on the outside and nearly cooked through, about 4–6 minutes. Remove the chicken and set aside.

In the same skillet, add the remaining 1 tablespoon butter and the last tablespoon of oil if the pan is dry. Sauté the minced garlic and diced onion over medium heat until soft and translucent, about 4–5 minutes.

Pour in the tomato sauce, then stir in sugar, 1 teaspoon salt (adjust to taste), ½ teaspoon black pepper, and the remaining ½ teaspoon curry powder. Bring to a gentle simmer to meld flavors for 5 minutes.

Reduce heat to low and stir in the heavy cream and cayenne pepper if using. Return the seared chicken to the skillet and simmer gently until the chicken is fully cooked and the sauce thickens slightly, about 8–10 minutes. Stir in the garam masala at the end for aromatic finishing flavor.

Swirl in any remaining butter for extra richness and sprinkle with freshly chopped parsley if desired.

Serve hot with warm naan and steamed rice for soaking up the creamy sauce.