Preheat oven to 425 degrees F.
In a large bowl, toss carrots, sweet potatoes and russet potatoes with olive oil, brown sugar, cinnamon, cayenne, salt and pepper.
Roast for 30 minutes, or until vegetables are tender and caramelized. Sprinkle finished vegetables with orange juice as soon as you take them out of the oven.
While the vegetables are roasting, make the pesto.
Place basil, cilantro, garlic, lemon juice and tahini in a blender and process.
Then drizzle in olive oil with the motor running and process again until smooth.
Season will salt and pepper to taste to taste.
Serve vegetables immediately with pesto and pomegranate arils on top. You can make the pesto up to 3 days ahead of time.