Brown chorizo in large deep nonstick skillet over medium-high heat. Season ground beef, if desired, with salt and pepper. Add ground beef and onion to same skillet and cook over medium-high heat, stirring occasionally, until beef is browned and onions are tender, about 5 minutes.
Stir in chili powder and cook, stirring, until fragrant, about 30 seconds. Add water, beans and corn and bring to a boil over medium-high heat.
Stir in Knorr(R) Fiesta Sides(TM) - Spanish Rice; reduce heat and simmer covered until rice is tender, about 7 minutes. Stir in tomatoes and let stand 2 minutes before serving. Serve, if desired, with lime wedges, corn tortillas and chopped cilantro, scallions and avocado.