Smashed Fingerlings with Jalapeños

Ingredients:

3 pounds fingerling potatoes, halved crosswise if large

½ cup olive oil, divided

Kosher salt and freshly ground black pepper

¼ cup Sherry vinegar or red wine vinegar

1 tablespoon whole grain mustard

1 jalapeño, thinly sliced into rounds, seeds removed if desired

¼ cup (lightly packed) torn flat-leaf parsley leaves

Preparation:

1.Preheat oven to 450°. Toss potatoes with ¼ cup oil on a rimmed baking sheet; season with salt and pepper. Roast, tossing once, until golden brown and tender, 30–35 minutes. Let cool slightly, then lightly flatten.

2.Meanwhile, whisk vinegar and mustard in a large bowl. Gradually whisk in remaining ¼ cup oil until emulsified; season with salt and pepper. Add potatoes, jalapeño, and parsley and toss; season with salt and pepper.