Rhubarb and Custard Crumble Tart

• 170 g plain flour
• 110 g chilled butter, cubed
• 55 g

Preheat the oven to 200°C/400°F/Gas 6.

Put a baking sheet in the oven as it heats up.

To make the crumble put the flour and butter together with a pinch of salt into a large mixing bowl. Rub together until the mixture resembles coarse sand. Stir in the sugar, then scatt