Begin by thoroughly washing and drying the mixed salad greens in a salad spinner or by patting them gently with paper towels. Once dry, place the greens in a large, colorful salad bowl.

While the greens are drying, rinse the fresh blueberries under cold water and lay them out on a clean towel to dry. Next, chop the shelled pistachios into coarse pieces, crumble the feta cheese, and thinly slice the red onion.

In a small bowl, whisk together extra virgin olive oil, honey, balsamic vinegar, Dijon mustard, salt, and pepper until well combined and emulsified, which should take about 1-2 minutes.

With all ingredients prepped, add the blueberries, chopped pistachios, crumbled feta, and sliced red onion to the bowl of mixed greens. Gently toss everything together.

Pour the prepared dressing over the salad mixture, ensuring even coverage. Use salad tongs to gently toss the ingredients together until nicely coated.

Serve the Blueberry Pistachio Spring Salad immediately for maximum freshness and flavor, or chill briefly before serving.