In a 2- to 3-quart pan over high heat, bring quinoa and 2 1/2 cups water to a boil. Reduce heat and simmer, covered, until water is absorbed, 10 to 15 minutes. Rinse to cool; drain well.
Meanwhile, in a bowl combine lime juice, oil, cumin, beans, corn, jicama, roasted peppers, cilantro, onion, and chili. Mix in quinoa, then season to taste with salt. Spoon over lettuce leaves.