Method

• 1.
  For pastry, blitz walnuts in a food processor until finely ground. Add flour, pulse to combine, then add butter and pulse until mixture resembles breadcrumbs. Place in a bowl, add water and, using your hands, mix to form a firm dough; add a little more water if necessary. Form into a disc and wrap in plastic wrap. Refrigerate for 30 minutes.
• 2.
  Steam cauliflower for 6 minutes or until nearly tender. Place in a colander to cool.

• 3.
  On a lightly floured surface, roll pastry out to a 45cm x 17cm rectangle, 3mm thick. Transfer to a 34cm x 11.5cm non-stick tart tin with a removable base. It will be fragile; patch up any tears, pressing firmly together. Trim around top of tin. Refrigerate for 30 minutes. Preheat the oven to 200°C.
• 4.
  Line pastry with a piece of baking paper, fill with baking beads or dried beans and bake for 10 minutes. Reduce heat to 180°C and bake for another 10 minutes. Remove paper and beans and bake for 3-4 minutes until dry to touch. Scatter with 125g (11⁄4 cups) cheddar, then the cauliflower.
• 5.
  Beat eggs, yolk and cream in a bowl, season well, then carefully pour mixture over cauliflower and cheddar. Scatter with remaining cheese and the sage leaves and bake for 50 minutes or until set and golden. Cool slightly, then slice and serve.