So much more economical than paying $5.00 for a tiny bit of crème fraiche. You can use any leftovers (if you have any!) for making a pan sauce for chicken or pork chops or whatever else takes your fancy. Experiment using in other ways too, enjoy!
Combine in a jar, 1 cup whipping cream (I recommend Avalon), 2 tsp. sour cream, yogurt or buttermilk. Cover with plastic wrap & secure with an elastic band. Shake vigorously. Remove elastic band and loosen the plastic wrap slightly. Let stand in a warm spot shaking a few times a day, until thickened to the consistency of thick yogurt. This could take up to 36 hours. Once thickened, you can store in the fridge for a couple of weeks.
Mixing equal amounts of crème fraiche & sour cream together with sugar to taste, makes a very good topping for a fruit pie or fruit tart.