
Place the potatoes in a pan of salted water over medium heat. Bring to the boil then reduce and simmer for about 15 minutes or until fork tender. Drain, rinse and allow to cool.
Add the onions to a small bowl with the lemon juice and allow to stand for 10 minutes.
Using separate bowls, mix dressing one and two together using the listed ingredients.
Add potatoes to a large bowl. Toss with celery, radishes, gherkins, herbs with dressing one, before adding dressing two and serving.