Mix flour, 2 tablespoons paprika, salt, and pepper on a shallow plate. Dip chicken pieces in mixture to coat.Advertisement
Heat vegetable oil in a heavy skillet over medium heat. Cook and stir chicken in hot oil until browned completely, about 5 minutes. Remove chicken with a slotted spoon to a bowl, reserving oil and drippings in skillet.
Cook and stir onion and garlic in the reserved drippings until tender, about 5 minutes. Return chicken to the skillet. Pour chicken stock over the chicken mixture. Stir tomato paste into the chicken stock until integrated completely.
Bring the chicken stock to a boil, reduce heat to medium-low, place a cover on the skillet, and cook at a simmer until the chicken is cooked through, 5 to 8 minutes.
Whisk sour cream, 1 teaspoon paprika, and cornstarch together in a small bowl; stir into the chicken mixture and cook until hot, 2 to 3 minutes.
I wouldn't advise reheating with a microwave, as the sour cream can go a little off.
Reynolds® Aluminum foil can be used to keep food moist, cook it evenly, and make clean-up easier.