This is the dressing I'd use with new potatoes. (Not fecking crushed).
1/2 teaspoon sea salt
2 cloves garlic, peeled
1 rounded dessertspoon mustard powder
1 tablespoon balsamic vinegar
1 tablespoon sherry vinegar
5 fl oz (150 ml) extra virgin olive oil
freshly milled black pepper
Crush the salt quite coarsely with a pestle and mortar, and then add the garlic. Ad you crush it and it comes into contact with the salt, it will quickly break down into a puree. Next, add the mustard powder and really work it in, giving it about 20 seconds of circular movements to get it well blended. After that, add some freshly milled black pepper. Now add the vinegars and work these in in the same way. Then add the oil, switch to a small whisk and give everything a really good whisking.
It's from Delia. But her recipe has way too much salt, so I've cut back.