Roll the pastry onto a flat baking tray, scoring a 1cm border. Prick inside the border all over with a fork, right down to the base of the tray. Spread the redcurrant jelly or chutney up to the scored border, then top higgledy-piggledy with the cheese, roasted squash, 1/2 the chopped nuts, and the rosemary. Brush the border with the beaten egg. Drizzle a dash of oil over the tart, season, then bake for 25 minutes, until very crisp and bubbling. Allow to cool for few minutes.