In a mixing bowl, combine chicken thighs with salt, garlic powder, sweet paprika, curry powder, and Greek yogurt. Cover and let marinate for at least 15 minutes.

Heat vegetable oil in a large skillet over medium-high heat. Add the marinated chicken, cook for about 8-10 minutes until golden brown and fully cooked. Remove the chicken and set aside.

In the same skillet, reduce heat and add butter. Once melted, sauté minced garlic and diced onion for 3-4 minutes until the onion is translucent.

Stir in tomato sauce and sugar into the sautéed onions and garlic. Let the mixture simmer for 2-3 minutes until it thickens slightly.

Return the cooked chicken to the skillet and mix well with the sauce. Pour in heavy cream, stirring gently to combine. Let everything simmer on low heat for about 10 minutes.

Garnish with parsley if desired. Serve hot with naan bread and steamed rice.