Cut chicken breasts into thin, fajita size strips (about 1/2"). Make sure to cut against the grain.
Heat chicken in 1 Tbsp of vegetable oil over medium heat until cooked through.
Remove chicken from pan and add the other tablespoon of oil and all the remaining ingredients. Cook for about 10 minutes and then add the chicken back to the pan.
Simmer for a few minutes and then serve. Can serve just plain as is, or with corn or flour tortillas. Fills about 12 fajita-sized tortillas. Top with sour cream, guacamole and salsa for even more flavor!