Gather the ingredients so that you have everything close at hand on the counter or table.
In a large bowl, layer spinach, oranges, walnuts, and beets. Gently toss to combine.
Alternately, you may add spinach to individual bowls and then strategically place the mandarin oranges, beets, and walnuts on the salad. Doing so, will help eliminate any damage to the oranges or spreading of the beet juice.
Make the Dressing
In a small bowl, mix together Balsamic vinegar, honey, Dijon mustard, and freshly ground black pepper.
Slowly add extra virgin olive oil and whisk until the dressing emulsifies. If desired, pour into a cruet bottle for serving.
When ready to serve, drizzle vinegar dressing over salad. Sprinkle individual servings with Feta cheese as desired. Serves 4-6