Here's the recipe I've been using for over 30 years. Yummy!
1/4 cup butter 1/2 cup finely chopped onion 1 cup sliced mushrooms 1/4 cup flour 2 teaspoons paprika 1 teaspoon salt 1 teaspoon sugar 1 1/2 cup milk 1 cup sour cream 2 1/2 cup diced, cooked chicken or turkey Melt butter in heavy saucepan. Add onion and mushrooms, saute till mushrooms tender. Blend in flour, paprika, salt and sugar. Add milk and cook, stirring constantly until smoothe and thickened. Remove from heat, add sour cream. Add turkey and heat through, but do not boil or simmer. Serve over noodles.
There are lots and lots of different versions - some with diced; mine is with chicken parts although the recipe's at home. It's otherwise pretty similar. I've seen a number of regular supermarkets selling the nice brand of Paprika from Hungray - it says Szeged on it (that is the town where they grow the peppers). There is sweet paprika and hot paprika - I prefer the sweet and it's definitely what you'd get in a resaturant. Oh, and paprika should be stored in the refrigerator.
Yum! and yes, Budapest is my favorite foreign place.