You need
125 ml good quality mayonnaise or full cream yoghurt
125ml cultured buttermilk
2 cups, loosely packed, of soft leafed herbs of your choice: parsley, mint, fennel, tarragon
3-4 ml salt
3-4 ml ground black pepper
Juice of 1 large lemon
1 clove garlic
2-3 spring onions
Optional: 3-5 anchovies or 20 ml Anchovy essence/ concentrate
To prepare
Blend all the ingredients together until mixture is smooth