Blueberry apple cider vinaigrette
Blend all ingredients in a blender until smooth. Keep refrigerated.
Toss the spinach leaves in a small amount of the blueberry apple cider vinaigrette and place at the bottom of a large shallow bowl.
Layer the blueberries, lentils and apple on the bed of dressed spinach.
Drizzle with more vinaigrette and top with goat cheese (if using) and walnuts.