If your chicken breasts are uneven, pound them to an even thickness for faster and more even cooking.
Let the chicken marinate for at least 20-30 minutes, or up to 2 hours if you have time. Even a short marinate lets the spices penetrate the meat for more flavor.
I recommend using a cast-iron or nonstick skillet for best sear. If the chicken or veggies brown too quickly, reduce the heat slightly to avoid bitterness.
For crisp-tender peppers and onions, cook them on medium-high heat and avoid overcrowding the pan. You can cook in batches if needed.
To know if the chicken is cooked through push a bit on the thickest part. If it doesn’t give in much, it’s cooked. It should feel similar to when you push your thumb against your pinky. The proper temperature is165°F.
Letting the chicken rest a bit helps to set the juices. So if you cut it open after a bit of rest it won’t lose as many juices anymore.
Warm tortillas directly on the skillet for 15-30 seconds per side or wrap in foil and place in the oven at 350°F for a few minutes to make them soft and pliable.