Season the chicken on both sides with kosher salt, black pepper and garlic powder.
Heat oven safe pot over medium heat, add butter and brown chicken on both sides to form a nice crust. Transfer chicken to a plate and set aside and keep warm.
Add the onions to the same pot, and sauce until translucent. Add the peppers and tomatoes, stir until peppers are tender.
Add in the paprika, cayenne pepper and flour to the vegetables and continue to cook for about 3-4 minutes. Slowly add in the chicken stock while stirring and then season with kosher salt and pepper to taste and bring to a boil.
Return the chicken back to the pot. The liquid should cover the chicken by two-thirds (can add more stock if needed).
Cover tightly and place in the oven at 350F. Braise in the oven for about 35-40 minutes until the chicken is fork-tender.
Remove the pot from the oven and transfer the chicken to a plate. Set aside and keep warm.
Remove some of the fat (oil) from the top of the liquid with a ladle or paper towel. Return the pot to the heat, simmer until you reach your desired flavor and viscosity. Add the chicken back to the pot.
In a small bowel stir the sour cream and about a 1/4 cup of the liquid together then temper the mixture into the pot with the chicken. Taste and season as needed.
Can substitute Hungarian sweet paprika for regular paprika.