I want to make tenina's pesto potato salad ready for tomorrow.
It says to not mix it yet but rather "toss steamed potatoes with a little verjuice, lemon juice, white wine or champagne vinegar to prevent drying out". Does this mean I choose one of the items in this list to toss it in or all? And what is verjuice - something I can buy? Just out of interest as I'm not planning to buy it.