Position the turkey with the front facing away from you. Remove both wings. Hold the bird firmly with your left hand on top of the bird. Now with whatever very sharp knife that's suitable. (I use my chinese cleaver) make a series of HORIZONTAL cuts about 5/16" depending on how thick you want the slices starting at the lowest part of the breast through the breast meat until you feel the blade making contact with the breast bone. Don't remove any slices until you cut the whole breast this way. By making these horizontal slices you are cutting against the grain so the slices won't be stringy. You must keep the blade as horizontal as you can. When you've sliced the entire breast all the slices will still be attached to the breast bone if you've done it right. Now carefully with a small sharp knife just cut the slices away from the breast bone. You'll now have a stack of beautifully carved slices ready to serve. I'm attaching a diagram to see if it helps demonstrate this method better than my long winded post.