Method

• 1.
  Preheat the oven to 180°C.
• 2.
  In a large heavy-based saucepan, melt half the butter over medium-heat. Add onion and fry, stirring, for 6-8 minutes until soft. Add the leek and cook, covered, for 5 minutes until soft. Throw in the rest of the vegetables (keeping cauliflower aside) and cook, stirring, for 10 minutes until they get the occasional lightly tanned edge.

• 3.
  Add enough water to just cover the vegetables, season with sea salt and bring to the boil. Add the cauliflower and reduce to a simmer. Simmer for 6-8 minutes until the vegetables have softened a little bit, but are still firm. Spoon off any scum that floats to the surface. Taking care to save all the cooking water, drain the vegetables and set aside.
• 4.
  In a clean saucepan, melt remaining 45g butter over medium-low heat. Stir in the flour and cook, stirring, for 2-3 minutes until the mixture bubbles. Add 200ml reserved cooking water and whisk to combine. Add another 1 1/2 cups (375ml) water and cook until thick. Add the cream and cook for a further 1-2 minutes until the sauce is creamy and thick. Remove from heat, stir in cheeses and herbs, season and cool slightly.
• 5.
  Roll out the pastry on a lightly floured surface to a 4mm-thick round. Using a 1-cup (250ml) pie dish as a guide, cut out 6 pastry lids that are 3cm wider than the edge of the dish. Fill 6 pie dishes with the vegetable mixture, brush the rim with egg and place a pastry lid on top, pressing the edges to seal. Cut a hole in the centre to allow steam to escape. Brush pastry with egg and cook in the oven for 25-30 minutes until the pastry is golden brown and the filling is bubbling.