Thanks for posting Bergy, as I did not have to substitute sour cream in Crock Pot Normandy Pork With Apples, Shallots & Cider which turned out just wonderful. I'm saving this recipe, because it is simple and I will be using it again and again.
In my part of the world this is sold as Creme Mexicana. This recipe is so simple. The real trick is not getting the creme to hot. I liked the hint about putting it in the oven with the light on.