Rinse the quinoa with cold water in a fine mesh sieve. Transfer to a medium saucepan and add 1 ¾ cups water. Bring to a boil, cover and lower to a simmer. Cook for 15 minutes or until all water has been absorbed. Allow to sit off the heat, covered for an additional 10 minutes.

Prepare a large bowl of ice water. Bring a large pot of salted water to a boil and submerge the asparagus for 2 minutes. Drain and immediately plunge the asparagus in the ice water bath until cooled. Remove from the water, pat dry and cut into 1-inch pieces.

Prepare the vinaigrette: in a blender or a food processor, combine the onions, garlic, mint, vinegar, honey, salt and pepper. Turn the motor on and add the olive oil in a slow steady stream.

Place the spinach leaves in a large salad bowl. Add the quinoa, beets and asparagus to the spinach. Drizzle the dressing over the salad and toss to combine. Taste for seasoning.