Preheat oven to 400°F (200°C). Wrap beets individually in foil and roast for 40-45 minutes until tender when pierced with a fork.
Remove beets from oven and let cool completely before peeling and slicing into wedges.
Place chopped kale in a large bowl and drizzle with 1 tablespoon of olive oil. Massage the kale with your hands for 2-3 minutes until it becomes tender and darker in color.
Core and chop the apple into bite-sized pieces.
Roughly chop the walnuts.
In a small bowl, whisk together remaining olive oil, apple cider vinegar, maple syrup, and salt to taste.
Add the cooled beet slices, chopped apple, and walnuts to the massaged kale.
Pour the dressing over the salad and toss everything together until well combined.