Method Prep:10min › Extra time:30min chilling › Ready in:40min
Sift the flour and salt into a large mixing bowl. Mix in the oats. Add the butter and rub into the flour until the mixture resembles breadcrumbs.
Beat the egg with the cold water, and mix lightly into the flour mixture with a fork. With your hands, gather together into a dough, handling as little as possible. Add a drop more water only if the dough will not clump together.
Wrap the ball of dough in cling film and chill for at least 30 minutes before rolling out or pressing into a tart tin.