Preheat the oven to 400°F (200°C). Wrap each beet in aluminum foil and roast for 45-60 minutes until tender.
Allow the beets to cool slightly before peeling. Slice into wedges or cubes.
In a large bowl, combine mixed greens with a sprinkle of salt and drizzle with olive oil.
Add the sliced beets, crumbled feta, and toasted walnuts to the greens.
In a small bowl, whisk together balsamic vinegar, olive oil, honey, salt, and pepper for the dressing.
Drizzle the dressing over the salad and toss gently to combine.
