Fig.1: With a 180° wrist turn (right hand), swing the short rope end up through the loop which has automatically been formed in the long rope part between the hands.

Fig.2: is the result.

Fig.3: With the left hand, lead the short rope end fromright to left around the back of the long rope part.
  Should you wish to have the short rope end on the outside of the knot, then lead the short rope end fromleft to right around the back of the long rope part.

Fig.4: and then, back down through the loop. The short rope end in this bowline lies in the middle.