Preheat oven to 400°F (200°C). Place beet wedges on a baking sheet, drizzle with 1 tbsp olive oil, season with salt and pepper, and roast for 30–35 minutes until tender.
While beets roast, prepare dressing: whisk together balsamic vinegar, honey, Dijon mustard, and 1 tbsp olive oil. Set aside.
Toast walnuts in a dry skillet over medium heat for 3–4 minutes, stirring frequently until fragrant.
Arrange mixed greens on a serving platter. Top with roasted beets, crumbled goat cheese, and toasted walnuts.
Drizzle with dressing just before serving.