Place a steamer basket in a large skillet or pot. Add water to just below the basket. Bring to boiling; reduce heat. Add sweet potatoes to basket; cover. Steam 10 minutes. Add bok choy; cover. Steam 5 minutes more or until tender.
Meanwhile, for Miso Dressing, in a small bowl whisk together the ginger, miso, lime juice, cider vinegar, maple syrup, and garlic. Gradually whisk in canola oil until combined.
Serve veggies over quinoa; drizzle with Miso Dressing. Garnish with sesame seeds, if desired.