01 - Set oven temperature to 400°F.
02 - Wrap each beet individually in aluminum foil and arrange on a baking sheet. Roast for 40 to 50 minutes until tender when pierced with a knife.
03 - Allow beets to cool until manageable. Peel and cut into wedges or bite-sized cubes.
04 - In a small bowl, whisk together olive oil, balsamic vinegar, Dijon mustard, honey, salt, and black pepper until emulsified.
05 - Combine arugula, roasted beets, and sliced red onion in a large bowl. Drizzle with dressing and toss gently to coat evenly.
06 - Transfer salad to a serving platter and top with crumbled feta and toasted walnuts.
07 - Present immediately for optimal freshness and flavor.