Prepare Beef Rice-A-Roni^® according to package directions.

Meanwhile, in 10-inch nonstick skillet over medium-high heat, cook ground beef, mushrooms and garlic about 2 minutes. Stir in red pepper. Continue cooking 4 to 6 minutes or until beef is cooked through and no longer pink, stirring occasionally.

Combine beef mixture with cooked rice-vermicelli mixture; stir in corn and let stand 2 minutes. Garnish with green onion, if desired.