01 - Melt butter in a nonstick skillet over medium heat. Add walnuts and sugar, stirring constantly until sugar melts and evenly coats the nuts, approximately 3-4 minutes. Transfer walnuts to parchment paper, spreading them apart to cool completely and prevent clustering.
02 - Combine olive oil, balsamic vinegar, Dijon mustard, honey, salt, and pepper in a small bowl or jar. Whisk vigorously or shake until fully emulsified and smooth. Set aside at room temperature until ready to serve.
03 - Place baby spinach in a large salad bowl. Layer with sliced strawberries, thinly sliced red onion, and crumbled goat cheese evenly across the greens.
04 - Break apart any remaining clusters of cooled candied walnuts. Scatter them over the salad for even distribution of sweetness and crunch.
05 - Drizzle balsamic vinaigrette generously over the salad immediately before serving. Toss gently with salad servers to coat all ingredients evenly without damaging delicate components.