Use a knife or scissors to cut the top off the freezer bag. Then cut the sides of the bag, so as to form a large rectangle when opened. Place meat on one side of the plastic, and use the other side to cover it and form a barrier between the meat and the mallet. You can also use a few layers of plastic wrap for this if you don’t have a plastic freezer bag on hand. Pound the meat repeatedly with the flat side of the mallet until desired thickness is reached. You could also use a large, heavy pan, which has a larger surface area for larger pieces of meat. When pounding the meat, angle the blows slightly outwards, so that the meat spreads out evenly.
This kitchen tip will come in handy when preparing chicken breasts for stuffing or making schnitzel. As well as the mallet and pan methods, you could also use a rolling pin to flatten the meat, or you could roll out the meat as you would roll out pastry dough, just with a lot of extra force!