Potato salad

INGREDIENTS

• 2 tbsp walnut
• 1 tbsp tarragon
• 2 tsp Dijon mustard
• 2 tbsp olive oil
• 2 tbsp walnut oil
• 1 tsp honey
• flaked sea salt and freshly ground black pepper
• 900g/2lb new potatoes, such as Jersey Royals or Charlotte, washed or scrubbed
• 1 tbsp chopped fresh tarragon
• 1 large shallot
• 2 tbsp chopped cornichons or gherkins