First, soak the parsley in a deep bowl of water so that all the sandy bits sink to the bottom of the bowl. Give the herbs a bit of a shake in the water and leave for a few minutes.
Meanwhile, peel the potatoes and boil whole in a large pot of water until just tender, about 15–20 minutes.
While the potatoes are boiling, make the pesto. Drain the parsley and spin thoroughly in a salad spinner. (The drier your parsley, the smoother your pesto will be.) Pick the long stalks off the bunch and place the curly bits in the bowl of a food processor together with the garlic. Pulse until the parsley is thoroughly chopped. With the motor running, slowly drizzle in the vegetable oil. Now add the lemon juice and 1 teaspoon of salt and a solid grinding of black pepper. You should have a creamy, bright green pesto.
In a medium-sized bowl, gently break 4 of the potatoes with your fingers into rough bite-sized pieces. In this bowl, splash the potatoes with olive oil and season the potatoes generously with the salt. (Do not be shy. Potatoes need salt.) Sprinkle with red wine vinegar and then
You may not use up all the pesto but then you have delicious leftovers to put on sandwiches or stir through some fragrant rice.