Preheat the oven to 425°F. Cover the potatoes in water in a saucepan, cover the saucepan and bring to a boil. Drain the potatoes immediately, cut into wedges or thick slices, and scatter on a baking sheet. Drizzle with olive oil, season with salt and pepper, and roast until they're brown, about 30 minutes.
Combine in a large bowl the vinegar and mustard. Add about ¼ c. olive oil and stir until emulsified. Add the potatoes, eggs, cornichons, capers, shallots, paprika and salt and pepper to taste, and toss gently to coat. Fold in the parsley and taste for seasoning.
Recipe by The Domestic Front at https://www.thedomesticfront.com/perfect-picnic-potatoes-gribiche/