Preheat oven to 425° F or 218° C
Peel and cube sweet potatoes.
Peel and cut onion into wedges.
Slice top off the head of garlic.
Arrange veggies onto baking tray.
Spray veggies with olive oil if using.
Sprinkle seasonings over veggies.
Roast veggies for 30-35 minutes until crispy.
While veggies are roasting mix all dressing ingredients together except for water.
Stir a little water into the dressing at a time until it reaches your desired consistency.
When veggies are done serve over arugula and drizzle tahini dressing on top. Enjoy!