This vivid salad made with fresh spinach, jewel-like blackberries, and candied walnuts is an inspired combination.
Whisk together vinegar, orange juice, and salt. Add oil in a slow, steady stream, whisking until emulsified.
Put salad greens, blackberries, feta, and walnuts into a bowl. Drizzle with vinaigrette, and toss gently. Season with salt and pepper.