One of my go-to dinners... I have no idea where I got the recipe. It's a great do-ahead dinner; stuff can be cut up and marinated a day ahead of time (not too much more than 24 hours, though, or you'll have chicken ceviche. Interesting, but ew.) Once everything is cut up, it takes less than 15 minutes to cook.
1 package (1.25 lbs or so) chicken breasts
a couple tablespoons of Worcestershire sauce
Salt, pepper, red pepper flakes, garlic powder (or crushed cloves), chili powder to taste
2-3 red and green peppers
1 large red onion
guacamole or avocado
In quart-size ziploc bag, squeeze lime and add several dashes of Worcestershire sauce.
Cut onion and peppers lengthwise into thin strips; set aside.
Cut chicken into thin strips; sprinkle a generous amount of salt, pepper, red pepper flakes, garlic powder, and chili powder on top. Put seasoned chicken into ziploc bag; squish out all of the air, and it should be covered in marinade. Refrigerate until ready to use (anywhere from a few minutes to until the next day. Of course, the longer you marinate the chicken, the tastier it will get.)
Add a little oil to a large frying pan; heat up until oil just starts smoking. Add onions and peppers; cook until onions just start to turn translucent, maybe 5 minutes. It's OK if the peppers char; actually, it's delicious.
Remove veggies to a bowl; add more oil to the pan if necessary. Add the chicken strips to the pan, laying them out so they're flat and in one layer. Do two batches, if needed-- don't crowd the pan! After a couple minutes, flip; they won't take too long to cook.
Serve with tortillas and anything that you think is good on a burrito.