Using a large skillet, or cast iron pot, over medium heat, add butter or oil and once heated, add chopped onions and sauté for about 4-5 minutes, until they are transparent. Stir in sweet paprika and black pepper and mix in with the onions.
Add chicken pieces to the skillet, skin side down and cook for 3-4 minutes, once browned, flip pieces and cook for another 3-4 minutes. Juices from the chicken will start forming.
Once chicken is browned, add chicken broth, tomato and hot pepper (if using). The liquid should almost cover the chicken pieces. Season with salt and partially place the lid on the skillet/pot and reduce heat to simmer so it's a slow boil for 40 minutes, remove lid and cook for another 15 minutes. Chicken should be cooked and tender.
To a make the creamy thick sauce, add the sour cream and flour/starch into a medium bowl, then add some of the sauce from the skillet into the bowl, and mix well using a wire whisk until you get a smooth consistency. Turn up the temperature to a medium boil and slowly add the sour cream mixture and move the chicken to the sides of the skillet and mix well with the wire whisk. Once it thickens, should take about 3-5 minutes, remove the skillet from the heat.
Serve with homemade dumplings or pasta. ENJOY!
If you like spicy food, you could substitute the hot pepper for a half of a teaspoon of the hot paprika in addition to the sweet paprika. Either way, you will go back for seconds!