Heat your oven to 425 degrees. Peel and slice the carrots into long strips. Slice the onion into thin strips, and thinly slice the garlic. Place the carrots, onion, garlic, and potatoes onto a large baking pan, and mix with the olive oil, cumin, chili powder, and salt.
Roast the veggies for 20 minutes, then stir, and roast for a final 20 minutes.
Make the dressing: combine the mustard, agave, oil and lemon juice into a medium bowl, and stir well.
Plate the spinach salad, then add the roasted veggies, and add your toppings of choice. We love this with garbanzo beans (rinsed and drained), hemp seeds, and dried cranberries. Top with the agave mustard dressing, and enjoy!