1tbsp cider vinegar
1tsp English mustard (Tewkesbury or Norfolk)
1 garlic clove, peeled
A few sprigs of tarragon
2tbsp extra virgin rapeseed oil
3tbsp vegetable or corn oil
Salt and freshly ground black pepper
Put all the ingredients into a clean bottle or jar. Give them a good shake and leave to infuse for at least an hour, preferably overnight, at room temperature. Strain the dressing before tossing with your salad.