In a bowl, combine the all-purpose flour, 2 tablespoons of paprika, sea salt, and black pepper.

Take your chicken pieces and dredge them in the flour mixture, ensuring they are well-coated.

Heat the vegetable oil in a large Dutch oven over medium-high heat. Brown the chicken pieces on both sides for about 3 minutes each until golden brown, then remove them from the pot.

In the same pot, add the chopped onion and optional cayenne pepper. Sauté for around 2 minutes, until the onion becomes tender and translucent.

Return the browned chicken to the pot, then pour in the chicken stock. Bring to a boil; once bubbling, reduce heat, cover, and let simmer for about 45 minutes.

To thicken the sauce, whisk together the remaining flour, sour cream, and ½ cup of the liquid from the pot until smooth. Gradually stir this mixture into the sauce off heat, and simmer for another 5 minutes.