Preheat oven to 400 degrees.
Toss zucchini, sweet potato, onion and bell pepper with olive oil and salt. Evenly spread on two baking pans and bake for 15 minutes. Turn vegetables and bake for another 10-15 minutes or until done. Set aside to cool.
Combine roasted vegetables with arugula and quinoa. Stir in 4 tablespoons balsamic vinaigrette and grated cheese. Taste and add additional balsamic vinaigrette, if desired. Serve immediately or keep refrigerated for up to one day.
Tip: This salad is great for weekday lunches but keep the ingredients separate until the day you plan to eat it so the arugula stays fresh.