2 1/2 pounds baby red potatoes, cut into 1-inch cubes
2 tablespoons apple cider vinegar
1 tablespoon olive oil
1/2 cup whole buttermilk
1/4 cup reduced-fat sour cream
1/4 cup reduced-fat mayonnaise with olive oil
1 tablespoon Dijon mustard
2 carrots, grated
1/2 cup chopped celery
1/2 cup sliced radishes
1/2 cup steamed, cut fresh green beans
1/4 cup finely chopped fresh parsley
1 tablespoon lemon zest
1 garlic clove, minced
Sea salt and freshly ground pepper to taste
Bring potatoes and salted water to cover to a boil in a large saucepan; reduce heat, and simmer 7 to 10 minutes or until tender. Drain. Place potatoes in a large bowl; sprinkle with vinegar and oil, and toss gently. Cool completely (about 1 hour).
Whisk together buttermilk and next 3 ingredients. Stir in carrots and next 6 ingredients; season with salt and pepper to taste. Spoon buttermilk mixture over potato mixture; toss gently to coat.
Cover and chill 1 to 24 hours before serving.