01 - In a small mixing bowl, whisk together extra virgin olive oil, balsamic vinegar, Dijon mustard, honey, sea salt, and black pepper. Continue whisking vigorously until the mixture is fully emulsified and thickened slightly. Set aside at room temperature while preparing the salad components.
02 - Place the washed and dried baby spinach in a large salad bowl as the foundation. Add the sliced strawberries, toasted chopped walnuts, thinly sliced red onion, and crumbled feta cheese (if using) in an even layer over the spinach leaves.
03 - Drizzle the prepared balsamic vinaigrette evenly over the salad. Using salad tongs or large spoons, gently toss the salad to distribute the dressing thoroughly, ensuring all spinach leaves and ingredients are lightly coated without bruising the delicate greens.
04 - Transfer the dressed salad to individual serving plates or serve family-style in the large bowl. For presentation, garnish with additional walnut pieces or fresh strawberry slices if desired. This salad is best enjoyed immediately while the walnuts remain crunchy and the spinach stays crisp.