01 - Preheat the oven to 400°F.
02 - Individually wrap the beets in foil and arrange them on a baking sheet. Roast for 35 to 40 minutes until tender when pierced with a fork. Remove, unwrap, and cool.
03 - Peel the cooled beets and slice into wedges or cubes.
04 - Toast walnuts in a dry skillet over medium heat for 3 to 4 minutes, stirring frequently until fragrant. Allow to cool.
05 - Whisk together olive oil, balsamic vinegar, Dijon mustard, honey, salt, and pepper in a small bowl to emulsify.
06 - Toss the arugula with half of the dressing in a large bowl. Arrange dressed arugula on serving plates.
07 - Top arugula with roasted beets, red onion slices, toasted walnuts, and crumbled goat cheese if desired. Drizzle with remaining dressing.
08 - Serve immediately for optimal freshness.