Salad:
Citrus Dressing:
Preheat the oven to 400°F. Line a baking sheet with parchment paper.
Toss carrots and beets with olive oil, salt, and pepper. Spread evenly on the baking sheet.
Roast for 20-25 minutes, stirring once, until tender and slightly caramelized.
In a small bowl, prepare the Citrus Dressing. Whisk together orange juice, lemon juice, honey, olive oil, and Dijon mustard.
In a large bowl, toss roasted vegetables with baby spinach, sunflower seeds if using, and drizzle with dressing. Serve warm or at room temperature.