According to Culinaria Hungary, "In western Europe chicken paprikas became a prize-winning dish at the end of the 19th century, when Georges August Escoffier, the famous French chef, put Poulet au Paprika on the menu at the splendid Grand Hotel in Monte Carlo." It remains one of the most famous, and most comforting, of all Hungarian dishes.
Heat the oil in a large skillet over medium-low heat and cook the onion, stirring occasionally, until transparent.
Add the paprika and stir to combine.
Add the chicken and cook over high heat for a few minutes, stirring often.
Lower the heat, season with salt and add the red pepper and tomato. Stir to combine and cover with a lid. Cook until the chicken is cooked through, about 20 minutes, stirring only occasionally. Add a little water if the pan is too dry.
In a separate bowl, stir together the sour cream and flour until smooth. Add to the skillet, stir, and gently simmer for another 4 to 5 minutes.
Remove from the heat and serve with buttered egg noodles (the traditional accompaniment is actually a cucumber salad).
Notes
Gluten free if you substitute the little bit of flour at the end for gf flour or a teaspoon or corn starch.
Recipe by Katherine Martinelli at http://www.katherinemartinelli.com/blog/2012/chicken-paprika-food-bloggers-support-for-sandy/