900g/2lb new potatoes, such as Jersey Royals or Charlotte, washed or scrubbed
2 tbsp chopped cornichons or gherkins (optional)
1 large shallot, finely chopped
1 tbsp tarragon or cider vinegar
1 tbsp chopped fresh tarragon leaves
2 tsp Dijon mustard
flaked sea salt and freshly ground black pepper
1 tsp runny honey or maple syrup
2 tbsp olive oil
2 tbsp walnut pieces (optional)
2 tbsp walnut oil