For the potatoes in the beauty bath melt butter in a pan, add flour by stirring constantly and on low heat. Then whisk in milk and simmer until it becomes nice and plump. Season with soup powder, salt and pepper, add cream and season with the pickle water. But be careful not to make it too sour. Cut the gherkins and potatoes into bite-sized slices. Then simmer in the béchamel sauce for a few minutes and season with pepper at the end.