You will see that I use double cream in many of the recipes in this book. This is because its high fat content makes it more stable for all methods of cooking than creams containing less fat (double cream contains 48% fat, whipping 35% and single 18%). Double cream thickens as it bubbles, with no risk of splitting or curdling. I wouldn’t recommend that you substitute yoghurt, fromage frais or crème fraîche where these are not already specified in the recipe. They are unlikely to give the dish the desired consistency, and the level of acidity is often unsuitable for the overall effect and taste of the recipe.