In a large mixing bowl, combine a pound of chicken breast or thighs with salt, garlic powder, paprika, curry powder, and Greek yogurt. Mix until the chicken is well-coated and let it marinate for at least 15 minutes.

Heat a large skillet over medium-high heat and melt half of the butter with olive oil. Add the marinated chicken in a single layer, searing for 4-5 minutes until golden brown, then remove and set aside.

In the same skillet, add the remaining butter and let it melt. Add minced garlic and diced onion, sautéing for 2-3 minutes until soft and translucent.

Stir in the tomato sauce, sugar, salt, black pepper, curry powder, and cayenne pepper. Let it simmer on medium heat for about 5-7 minutes.

Reduce the heat to low and stir in the heavy cream, letting it simmer gently for 5-7 minutes until thick and velvety.

Return the seared chicken to the skillet, stir in garam masala, and let it simmer on low heat for 8-10 minutes to absorb flavors.

Garnish with chopped fresh parsley or cilantro just before serving. Serve hot with naan or steamed basmati rice.