Whisk the dressing ingredients until well combined. Set aside.Meanwhile, heat oven to 425. Toss the diced sweet potato and apple on a large metal rimmed baking sheet with 1 tablespoon oil until evenly coated. Roast for 10 minutes, flip, then roast another 10 minutes, or until tender. Season with salt. Cool to room temperature. You can roast and refrigerate the sweet potato and apple up to two days before assembling the salad.Gently toss the arugula and spinach with the roasted sweet potato and apple, pear, pecans, and dressing. Serve with black pepper.