Preheat your oven to 400°F (200°C).
Roast the beets: Place the beets on a piece of foil, drizzle with olive oil, and sprinkle with salt and pepper. Wrap and seal. Place on a baking sheet and roast for 45–60 minutes, until fork-tender (larger beets may take a bit longer). Let cool slightly, then peel, the skins should slide right off, and cut into wedges or slices.
Make the dressing: In a small bowl, whisk together the olive oil, vinegar or lemon juice, Dijon mustard, maple syrup, salt, and pepper until smooth.
Assemble the salad: Arrange the greens on a large platter. Top with the roasted beets, oranges, red onion, toasted nuts, crumbled vegan cheese or dollops of yogurt, and fresh herbs. Drizzle with dressing just before serving.
