Pound chicken breasts between two sheets of wax paper to make them thinner and more even in thickness.
Place chicken in a dish and fill dish with water so the water level comes up about 1/3 of the way on the chicken.
Cover with wax paper or plastic wrap and cook in microwave on high for 4-5 minutes per breast. Use a thermometer to check temperature. Meat should be 165 degrees F.
Allow to cool and then shred or slice.
Video
Notes
You can use this method for chicken breasts or chicken tenderloins. Tenderloins will cook much quicker, about 5 minutes.
I generally use this method if I am only cooking 1-3 chicken breasts, for more I will use the slow cooker or Instant Pot.
Shredded chicken freezes well. Store in an airtight container or zippered plastic bag, remove as much air as you can and it will store for 2-3 months in the freezer.