OK so it wasn't an Eskimo Roll. Ian worked his way around the bow once it was upright and boarded from the windward side. Thanks Ian.

Ian Hopwood Eskimo Roll

Firstly, grab the centreboard and try to get the mast horizontal. Don't continue to right it until the wind has blown the hull around so you will be on the windward side when it does right. You can assist the bow to turn through the wind by using your feet to propel the hull. Once you are on the windward side thrust up close to the thwart, grab the capping front toe hole and in you go. The trick is positioning the hull before you try and right it. Once in, lift the board a little and keep your weight on the windward side to assist with turning the boat slightly away from the wind. As said before, getting the tension off the controls is also a priority. Get hold of the tiller extension and keep it neutral otherwise you might go into a windward roll