This partially soured, tangy cream has the added bonus of not separating during cooking. It is made by mixing buttermilk, sour cream or yogurt with double cream, heating it, then letting it stand. Stir, cover and refrigerate crème fraîche after it has thickened. Use it as the French do - as a flavouring for soups, sauces and savoury dishes. It is also delicious with fruits and sweet dishes.
Mix 500 ml buttermilk and 250 ml double cream. Put bowl over a pan of hot water and heat to 30°C.
Pour warm mixture into glass bowl; partially cover. Let stand at room temperature for 6-8 hours.