First let's trim the excess fat off the breasts. Then cut the narrow, pointy end off the breasts and horizontally slice the remaining thick part of the breast in half. Perform this surgery on all of the breasts. I buy a package of 4 - 5 boneless skinless breasts and cut them up like this.
Put a stovetop grill, or two of your largest skillets, on the stove at medium high and spray oil them. Put the pieces of chicken in a large plastic bag or cover them with plastic wrap. Use the flat side of a meat mallet or a rolling pin or the bottom of a saucepan to flatten the chicken pieces getting them as close as possible to all being equal in thickness.
Salt, pepper and garlic powder the filets.
Spread the filets out on the grill - or skillets - and cook for 4 - 6 minutes a side depending on the thickness. When the juices run clear or the middle of the thickest filet reads 170°F on an instant read meat thermometer they are done. Cook them in batches if necessary.
Remove them to a platter to cool a little.
Then serve some for tonights supper.
And put the rest into zip locks and into the freezer for some future quick and easy meals.