In a mixing bowl, combine the chicken thighs with salt, garlic powder, sweet paprika, curry powder, and Greek yogurt. Use your hands to coat the chicken evenly and let it marinate for 15 minutes at room temperature.

Heat 3 tablespoons of vegetable oil in a skillet over medium-high heat. Once hot, add the marinated chicken pieces, spreading them out in a single layer. Cook for 8-10 minutes, turning occasionally, until golden brown and cooked through. Remove the chicken from the skillet and set aside.

Lower the heat to medium and add 1 tablespoon of butter to the same skillet. Add the minced garlic and diced onion, sautéing until the onion becomes translucent and fragrant for about 3-4 minutes.

Stir in the tomato sauce and sugar into the skillet, mixing well. Let the mixture simmer for 2-3 minutes, then return the cooked chicken to the skillet.

Pour in the heavy cream, stirring gently until the sauce is smooth and creamy. Simmer on low heat for 10 minutes.

Stir in the remaining tablespoon of butter until melted and remove from heat. Garnish with fresh parsley.

Serve hot with warm naan bread and fluffy rice.