Preheat oven to 425°. Leave 1-inch of roots and stems on beets. Scrub well. Place beets on a large piece of heavy foil. Drizzle with 1 tablespoon olive oil; sprinkle with ¼ teaspoon salt and ¼ teaspoon pepper. Wrap tightly; place in a large rimmed baking pan.

Roast beets for 45 to 60 minutes or until tender. Cool slightly; rub off skins with paper towels. Remove and discard roots and stems. Cut beets into thin slices, then cut slices in half; set aside.

Peel Cara Cara, mandarin oranges, and lime. Slice oranges; cut segments from lime. Cover and refrigerate citrus fruit. For dressing, combine Cara Cara orange juice and lime juice. Whisk in remaining 1 tablespoon olive oil, vinegar, remaining ¼ teaspoon salt, and remaining ¼ teaspoon pepper.

To serve, combine yogurt and fermented honey in a small bowl. Spread mixture onto 4 serving plates. Top with beets, orange slices, lime segments, fennel, pearl onions, and kale. Spoon dressing over each salad. Garnish with fennel fronds and course ground pepper, if desired.