500g baby leeks, trimmed
1tbsp Dijon mustard
50ml white wine vinegar
200ml olive oil
1 small shallot, peeled and finely diced
1 garlic clove, peeled and crushed
6 sprigs tarragon
Place the trimmed leeks in a large saucepan of lightly salted boiling water and blanch for 2-3 minutes until they are just soft.
To make the vinaigrette, mix all the other ingredients together in a shallow dish.
Drain the leeks, add to the dish and coat in the vinaigrette while they are still warm, then leave to cool in the dressing. Serve at room temperature.