You can substitute boneless skinless chicken thighs for the chicken breasts.
How long you cook the peppers and onions is up to you. Cook them until they have a light char if desired!
Depending on how much heat you like in a recipe, remove seeds and pith before chopping the jalapeño peppers. If you prefer more heat, add in some or all of the pith and seeds.
You can make a full batch of our fajita marinade and use 1 cup for this recipe. Store the remaining marinade in a glass container in the fridge for up to 7 days or freeze it for up to 4 months.