01 - In a small mixing bowl, combine extra virgin olive oil, balsamic vinegar, Dijon mustard, honey or maple syrup, sea salt, and freshly ground black pepper. Whisk vigorously until fully emulsified and slightly thickened. Set aside at room temperature while assembling the salad.
02 - Place the washed and dried baby spinach in a large salad bowl, creating a generous bed of greens. Arrange the sliced strawberries, toasted walnuts, and thinly sliced red onion evenly over the spinach. If using, sprinkle the crumbled feta cheese across the top as the final garnish.
03 - Drizzle the prepared balsamic vinaigrette evenly over the salad. Using salad tongs or large spoons, gently toss the ingredients to combine, ensuring each spinach leaf is lightly coated with dressing. Avoid over-tossing to prevent bruising the delicate greens and crushing the strawberries.
04 - Transfer the dressed salad to individual serving plates or serve family-style in the large bowl. For an elegant presentation, garnish with additional toasted walnut pieces or fresh strawberry slices. This salad is best enjoyed immediately while the spinach remains crisp and the walnuts retain their crunch.