Begin by combining chicken thighs in a mixing bowl with salt, garlic powder, sweet paprika, curry powder, and Greek yogurt. Toss everything thoroughly to coat the chicken evenly. Cover and let it marinate for at least 15 minutes.

Heat a large skillet over medium-high heat and add vegetable oil. Once the oil is shimmering, add the marinated chicken thighs. Cook for 8-10 minutes until golden brown and cooked through. Remove the chicken from the skillet and set aside.

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

Stir in the tomato sauce and sugar, allowing it to simmer for about 5 minutes to meld flavors together.

Return the cooked chicken to the skillet and mix it well with the sauce. Pour in the heavy cream and stir until the sauce turns orange. Let it simmer for 2-3 minutes.

Sprinkle in cayenne pepper, garam masala, and black pepper. Allow to simmer for 10 minutes, stirring occasionally.

Add the remaining butter, taste and adjust salt if necessary, then garnish with freshly chopped parsley or cilantro before serving.