For parmesan rough puff pastry, sift flour and a pinch of salt onto a work surface, add parmesan and herbs, mix to combine. Add butter, cutting it through flour mixture with a pastry scraper until roughly mixed. Make a well in the centre, add 100ml iced water, mix with pastry scraper until a dough just forms. Bring together with the heel of your hand to form a disc, wrap in plastic wrap and refrigerate to rest (20 minutes). Roll out on a lightly floured surface to form a 1.5cm-thick rectangle, fold shortest ends together to meet in the centre, then fold in half again to form a book fold. Wrap in plastic wrap, refrigerate to rest (20 minutes), repeat twice. Wrap in plastic wrap, refrigerate until required (see note).
Preheat oven to 180C. Combine oil, vinegar, thyme and lemon rind in a small bowl and season to taste. Place onion slices in a single layer on baking trays lined with baking paper, keeping slices intact (don’t separate into rings). Drizzle over half the oil mixture and roast until very tender and lightly browned (20-25 minutes), cool to room temperature.
Roll out pastry on a lightly floured surface to 5mm thick, cut out a 25cm-diameter circle. Place on a baking tray lined with baking paper, refrigerate to rest (30 minutes). Score a 1cm border partway through pastry, prick inside border with a fork, brush edges with eggwash. Spread goat’s curd within border, arrange roast onions on top, bake until pastry is risen, golden and cooked through (25-30 minutes). Drizzle over remaining oil mixture, serve hot with a leaf salad.