01 - Preheat oven to 400°F. Wrap each beet in aluminum foil and place on a baking sheet. Roast for 40-45 minutes until tender when pierced with a knife. Let cool, then peel and cut into wedges or cubes.
02 - While beets roast, toast pecans in a dry skillet over medium heat for 3-4 minutes, stirring occasionally, until fragrant. Set aside.
03 - In a small bowl, whisk together olive oil, balsamic vinegar, Dijon mustard, honey, salt, and pepper until emulsified.
04 - Arrange mixed greens on a large platter or individual plates. Scatter roasted beets and red onion slices over the greens.
05 - Sprinkle with crumbled goat cheese and toasted pecans. Drizzle with vinaigrette just before serving.