Making a Cooked Dressing

Popular in America - where it was originally made by the Shakers and used for coleslaws and other raw vegetable salads - this simple creamy dressing combines a mixture of egg yolks and sour cream and uses flour to thicken. Although heat is essential to the sauce, to prevent curdling the heat must be very gentle, so the dressing must be cooked over a bain marie.

1. In a heatproof bowl, whisk together 2 egg yolks, 125 ml cider vinegar, 125 ml water and 30 g melted butter. Whisk until well blended, then whisk in 2 tbsp sour cream until smooth.

   

2. Set the bowl over a pan of simmering water. Add 1 tbsp dry mustard, 1 tbsp plain flour, 70 g caster sugar and ½ tsp salt. Whisk until the dressing is smooth, thickened and well blended.