Pulse flour, butter, egg, sugar, and milk in a food processor to form a dough.
Mix the dough by hand, cover, and chill in the fridge for 20 minutes.
Roll out the pastry on a floured surface and line a 20cm tart case.
Chill the lined tart case in the fridge for two hours.
Preheat the oven to 200°C.
Bake the pastry blind with weights for 25 minutes until golden.
Remove weights, brush with egg wash, and bake for another five minutes.
Roast pumpkin and squash with sugar on a baking sheet for 40 minutes.
Blend the roasted pumpkin and squash in a food processor until smooth.
Reduce the oven temperature to 180°C.
Simmer cream, honey, and spices in a saucepan over medium heat.
Whisk beaten eggs while slowly pouring in the hot cream mixture.
Stir in the pumpkin puree and pour the filling into the tart case.
Bake the tart for 35 minutes until the filling has set and leave to cool.
Whisk egg yolks, sugar, and vanilla together in a bowl.
Heat milk to near boiling and whisk it into the egg mixture.
Simmer the mixture over low heat until thickened to coat a spoon.
Serve a slice of pie topped with the warm homemade custard.