Start with the cords open.
Cross the cords and pull one end through like you do for Chaire knot.
Bring the top loop back over the bottom loop.
Lift up the left side of the looped cords with index and long finger of left hand.
With right hand bring the right side of the in front of the loop made around your fingers and down behind your fingers and emerging between index and long finger. The new loop should be pass on the left hand side of the existing loop.
With right hand grasp the middle loop / the first loop around your finger. Left hand pulls the loop held between the index and the long finger towards the left, while right hand pulls the original loop towards the right. Note: I had to use my right hand to take the image, but it would be pulling the cords to the right of my fingers...
Finally tighten the knot and adjust the knot. .
Done. To reopen the knot pull the left side of the loop sticking down until the first part of the knot comes apart, then let go of the top cord your holding and continue pulling until the knot is undone