1. Toast quinoa and cumin seeds in pot over medium-high heat, 3 to 4 minutes, or until golden and fragrant, stirring constantly. Transfer to bowl.
2. Heat oil in pot; add corn, potato and shallots. Sauté 5 minutes, or until shallots are translucent. Add broth and soymilk, and bring to a boil. Stir in quinoa mixture. Reduce heat to medium-low, cover and simmer 10 minutes. Stir in bell pepper, cover and simmer 5 minutes, or until quinoa and vegetables are tender.
3. Remove from heat; stir in chopped cilantro. Season to taste with salt and pepper. Ladle into soup bowls, and garnish with cilantro sprigs and lime wedges, if desired.