01 - Preheat oven to 400°F. Wrap each beet individually in aluminum foil and place on a baking sheet.
02 - Roast for 40–45 minutes, or until beets are tender when pierced with a fork. Remove from oven and let cool slightly.
03 - Peel the beets while still warm, wearing gloves to avoid staining, then slice into wedges or rounds.
04 - Whisk together olive oil, balsamic vinegar, Dijon mustard, honey, salt, and pepper in a mixing bowl until emulsified.
05 - Arrange mixed greens on a large platter or individual plates. Top with sliced beets, crumbled goat cheese, toasted walnuts, and red onion.
06 - Drizzle dressing over salad just before serving and toss gently if desired.