Heat oven to 325°F (160°C). Heat taco shells from the kit according to package directions.
In 10-inch nonstick skillet, heal oil over medium-high heat until hot. Add chicken; cook 3 minutes on each side to brown.
Add enough water to skillet to come two-thirds of the way up sides of the chicken; cover skillet tightly. Reduce heat to medium-low; cook 13 to 15 minutes or until chicken is cooked through, tender and easy to shred. Cool 5 minutes.
Transfer chicken to plate or cutting board and shred with two forks. Discard the cooking liquid.
Return shredded chicken to the skillet. Add frozen corn, ½ cup water and the taco seasoning mix from the kit. Cook over medium heat 5 to 7 minutes until heated through and sauce is thickened.
Divide chicken mixture among the taco shells. Top with cheese, radishes and cilantro or any of your favorite taco toppings.
