Whisk together honey, mustard, salt and pepper in a small bowl. Whisk in lemon juice. Slowly add in olive oil in a steady stream. Whisk constantly until mixture is thick. Taste. Adjust salt and pepper as needed.
In a large bowl, toss spinach, blueberries and cucumber. Drizzle dressing over the salad. Toss to combine. Top with avocado, hard-cooked egg slices, and nuts