Prepare the pastry by adding the salt to the flour and then cutting in the butter until the mixture resembles fine breadcrumbs.
Add the egg and 1 tablespoon (15 ml) water, and combine the dough with a fork.
Add extra water, if needed, sparingly until the dough combines.
Wrap in plastic wrap and chill.
After half an hour, line a 10" (25 cm) quiche or pie dish with the pastry and return to the fridge.
Prepare the lemon glaze by combining butter, lemon juice, sugar and vanilla over low heat in a saucepan. Set aside.
Preheat oven to 425°F or 220°C.
Peel and core the apples and then arrange slices on the pastry in an overlapping circle. filling in the centre with additional slices.
Brush the apples generously with the lemon glaze mixture.
Bake for 15 minutes and then reduce temperature to 400°F or 200°C and continue to bake for an additional 20 minutes.
Meanwhile, whisk together the cream, 2 eggs and 1/2 cup (115 gm) sugar to combine.
Pour over the apples and bake for an additional 25 - 30 minutes at 375°F or 190°C until the custard is set and slightly browned.