The Guiding Hand  

The proper position and use of the guiding hand (left hand, if you are right-handed) is of paramount importance to ensure both a safe operation and consistent end food product.

With your left arm near your body, place the tips of your left fingers on the cutting surface. Allow the heel of your hand to fall to a point that your thumb can be placed behind your index finger touching it, thereby forming an "O" shape with your hand.

All four fingers should be together with your middle finger slightly forward in a natural position. Now, roll your hand forward so the tips of your finger rest behind the section of your finger between the first and the second joint from the fingertip. This forms the correct cutting position for the hand.

The flat section of the finger will form a guide for the knife to follow. As long as the knife blade is held flat and flush against the fingers and the knife is not raised higher than the finger knuckles and you keep your finger tip curled under and thumb behind, there is little chance of cutting yourself.

However, if all these fundamentals are not followed the use of the French knife may be come a very dangerous and painful situation. 

Using this form allows the thumb to push the product forward while the fingers are used as the cutting edge knife guide to ensure a consistent cutting motion which will result in a consistent finish food product.