Preheat broiler
Line a baking sheet with foil.
Place sweet potatoes on the baking sheet.
Sprinkle the olive oil over the potatoes and toss.
Season with a little salt and pepper and then place pan under broiler.
Roast the potatoes until they have just a little bit of browning 5-7 minutes.
Give the potatoes a stir and put them back under the broiler for another 2-3 minutes or so.
Remove from oven and cool.
Arrange the arugula on four plates.
Spoon ¼ cup of quinoa on to greens.
Scatter the sweet potatoes and cranberries on the salad.
Dress with vinaigrette and season with salt and pepper.