Cheese and caramelised onion tart

• butter↗50g g
• onion↗800g g

  (about 8 pieces), thinly sliced

• cream↗300ml ml
• ground nutmeg↗small pinch of
• egg yolks4

  (freeze the whites for another recipe, e.g., meringue)

• aged vegetarian cheddar↗100g g

  grated, plus extra for serving (optional)

• chives↗

  thinly sliced, for serving

• wheat flour↗200g g

  plus extra for dusting

• cold butter↗125g g

  cut into cubes

• egg↗1

  beaten

Step-by-step instructions

1. 1

   First prepare the dough. Put the flour and butter into a bowl, then rub them together with your fingertips until the mixture resembles coarse crumbs. Add the egg, then bring everything together with your hands just until combined. Form a disc. The dough can be wrapped and stored in the refrigerator for up to two days or frozen for up to a month.

2. 2

   Roll out the dough on a lightly floured surface into a disc about 28 cm in diameter. Using a rolling pin, lift it over a 23 cm tart tin, then line the tin. Press the remaining dough with a small ball against the bottom and sides of the tin, leaving excess hanging over. Chill in the refrigerator for 20 minutes. The tin can be prepared and chilled in advance, up to a day ahead.

3. 3

   Meanwhile, melt the butter in a pan over low‑medium heat and cook the onions for 45 minutes, generously seasoning and stirring occasionally until they become soft and golden. Pour in the cream, add the nutmeg and stir. Bring to a gentle boil, then remove from the heat.

4. 4

   Preheat the oven to 200 °C/180 °C convection/gas 6. Lightly prick the tart base with a fork, then line it with a large circle of parchment paper and fill it with ceramic beans, dry rice or lentils. Bake for 20 minutes, then remove the beans and paper and bake for another 10‑15 minutes until light‑brown. Break off a little of the overhanging crust to check doneness—it should be baked and crisp.

5. 5

   Meanwhile, whisk the egg yolks into the onion‑cream mixture, add two‑thirds of the cheese and stir. Pour into the crust, sprinkle the remaining cheese and bake for 20‑25 minutes, or until the filling thickens and turns golden. Let cool completely in the tin, trim the overhanging crust with a serrated knife, then remove from the tin. Sprinkle with chives and extra cheese if desired. Leftovers can be stored in the refrigerator for up to two days. Reheat in a low oven before serving.