Rinse quinoa well. Combine with 3/4 cup water in small saucepan. Bring to a boil. Cover, reduce heat and simmer 15-20 minutes or until water is absorbed and holes have formed in surface of quinoa. Remove from heat and cool to room temperature or cooler.
Dry toast pepitas by putting them in a large skillet or frying pan and shaking over high heat until they begin to pop and "dance". Remove from heat.
In food processor, combine pepitas, cilantro, lime juice, orange juice concentrate, olive oil, chili powder, cumin and salt. Blitz until a rough paste forms. (It looks a little funny at this stage--don't worry!).
In a very large bowl, combine veggies, quinoa and sesame seeds and toss. Add citrus-pepita dressing and mix well to coat. Chill at least one hour; overnight is ideal.