This simple pesto-like tarragon sauce has bright, clean flavors, and is delicious as a dressing for potato salad.
Why this recipe works:
- Adding salt and vinegar to the potato cooking water not only seasons the potatoes deeply, but the vinegar also prevents them from falling apart as they cook.
- Tempering the tarragon with parsley allows the tarragon flavor to come through without it being overwhelming.
Note: Espelette pepper powder is available at specialty food stores. You can also substitute a very small pinch of cayenne pepper.
- 1 1/2 pounds Yukon Gold potatoes, cut into 1/2-inch cubes
- Kosher salt
- 1/2 tablespoon red wine vinegar, plus more for covering the onion
- 1 small red onion, thinly sliced
- 1/4 cup picked tarragon leaves
- 1 cup loosely packed parsley leaves and tender stems
- 2 small cloves garlic
- 3/4 cup extra-virgin olive oil
- Pinch espelette pepper powder (see note)
- Freshly ground black pepper
- 1/2 cup pitted and halved black olives, such as Kalamata
Place potatoes, 1 tablespoon salt, 1/2 tablespoon vinegar, and 3 cups tepid water in a medium saucepan. Bring to a boil over high heat, stirring occasionally until salt is dissolved. Reduce to a bare simmer and cook until potatoes are completely tender and show no resistance when poked with a paring knife or cake tester, about 17 minutes. Drain potatoes and allow to cool to warm room temperature, about 10 minutes.
Meanwhile, add onion to a medium bowl and add just enough vinegar to cover. Let stand until onion is tender and lightly pickled, about 20 minutes.
Using a blender, immersion blender, or food processor, blend tarragon, parsley, garlic, and oil until well pureed. Mix in espelette pepper and season with salt and pepper.
Drain onions. In a serving bowl, toss potatoes with tarragon pesto, onions, and olives, and serve.
Blender, immersion blender, or food processor