This technique is used when your attacker throws a straight punch.
When your attacker throws the punch, step forward with your left foot and block the strike with a basic inside forearm block.
Twist anti-clockwise on the ball of your left foot and take your right arm behind your attackers back. Bend your left knee to pull your attacker onto your back. Also take your right foot off the ground ready for the stamp.
This part of the technique was difficult to photograph, so my attacker is not off the ground half way through the throw. However, you can see where you should be stamping as your lift your attacker onto your back.
As you stamp, twist your upper body to perform the throw.