In a large skillet over medium high heat, saute the rice vermicelli mix (dry rice from box) with margarine until vermicelli is golden brown.
Slowly stir in 2 cups water, salsa, chicken and special seasonings (from rice box) and bring to a boil. Reduce heat to low, cover and simmer 15 to 20 or until rice is tender and chicken is no longer pink inside.
Stir in beans and corn, let stand 5 minutes before serving. Serve in tortillas with cheese and sour cream, if desired.
Warm tortillas-wrap them in aluminum foil and bake in a 350 oven for about 5 minutes. Turn off the heat and keep them in the oven until ready to serve.