Cut: Slice the chicken breast as thin as possible using a sharp chef's knife.
Rack: Place strips of chicken onto a wire cooling rack that's set on top of a baking sheet. This will allow air to circulate around the chicken, while also catching any drippings.
Dry: Set on the middle rack of a 225°F (107°C) oven. Cook for 2 to 3 hours, flipping the chicken strips over after an hour, until chicken is crispy and dried out.
Notes
Store chicken jerky in an airtight container in the fridge for up to 2 weeks (the longer it is dried in the oven, the longer you'll be able to store them).