1. Line a 3.5cm x 22.5cm fluted tart tin with a brush of oil and then dust with flour, press the pastry sheets into the tart tin. Cut the excess off of the edges and line the pastry with baking paper and fill with rice. Place into a preheated oven at 200°C for 20 minutes. Remove rice and baking paper and set aside to cool.
  2. To make the caramelised onions, heat butter in a frypan and add the sugar, onions and garlic, sauté until browned and thick. Add to tart base along with crumbled feta and sprig of thyme.
  3. In a jug, whisk together the eggs and cream until combined and pour over onions, feta and thyme. Bake in a preheated oven at 180°C for 40 minutes.