Preheat oven to 200°C. Place the flour and butter in the bowl of a food processor and process until it resembles fine breadcrumbs. Add the egg yolk and water and process until dough just starts to come together. Turn onto a lightly floured surface and gently knead until just smooth. Shape into a disc and cover with plastic wrap, then place in the fridge for 30 minutes to rest. Roll out the pastry to a 15 x 40cm rectangle, about 3mm thick. Line a shallow 10 x 34cm (base measurement) fluted tart tin with a removable base with the pastry and trim any excess. Place in the fridge for 30 minutes to rest. Cover pastry base with baking paper and fill with pastry weights. Bake for 10 minutes. Remove paper and weights and bake for a further 10 minutes or until golden. Reduce oven to 160°C. Meanwhile, cook the asparagus in a saucepan of boiling water for 2 minutes or until bright green and tender crisp. Refresh under cold running water. Drain well. Arrange half the asparagus in the base of the pastry case. Whisk the egg, cream and cheese together in a medium bowl and pour over the asparagus. Arrange the remaining asparagus on top. Bake in oven for 30-40 minutes or until just set. Serve warm or at room temperature.