Blueberry & lemon custard brioche

To make the dough, put the flour into the bowl of a freestanding mixer fitted with a dough hook, add the yeast, sugar and salt, then use a balloon whisk to combine. Heat the milk in a small pan until lukewarm. Make a well in the centre of the dry ingredients, add the warm milk, 1 egg, the vanilla and lemon zest and mix on a slow speed until combined. Scrape down the sides of the bowl, then mix for 2 minutes until smooth.

Mixing slowly, gradually add the butter, then mix for about 5 minutes until the dough is silky-smooth and elastic and pulls away from the sides of the bowl. Scrape down the sides of the bowl again, scoop the dough into a clean bowl, cover with a clean tea towel and leave to prove overnight in the fridge (or for at least 4 hours).

Meanwhile, in a small pan, whisk together the custard, cornflour, lemon curd and zest. Bring to the boil over a low heat, whisking constantly, and cook for about 1 minute until thickened. Put in a bowl and cover the surface with damp baking parchment. Leave to cool, then chill until needed.

Once the dough has proved, line 2 baking trays with baking parchment. Turn the dough out onto a lightly floured work surface, knead it for a couple of minutes, then divide into 8 pieces (about 65g each). Shape each into a smooth ball with the seam on the underside. Flatten each ball into an 8-10cm disc and gently push down in the middle of each to create a nest shape with a 1cm border. Put 4 buns on each lined baking tray, loosely cover with a clean, damp tea towel and leave to prove at room temperature for about 1 hour, until risen and puffy.

Preheat the oven to 180°C, gas mark 4. Beat the remaining egg, then brush it over the borders of the buns. Spoon 1 tbsp of the chilled custard mixture into the middle of each bun, then spread it out to the border. Arrange the blueberries on top, then scatter with the poppy seeds. Bake for 17 minutes, until golden. Leave to cool to room temperature before eating.