1 tbsp lemon juice1/3 cup oats
2 tbsp all purpose flour
1 1/2 tbsp cold unsalted butter, chopped
Remove the dough from the refrigerator and let it sit at room temperature until slightly softened. Roll the dough into a 1/4 inch thick circle, slightly larger than a 9 inch tart tin. Press the dough into the tart tin with your fingers and trim away any excess. Make a few pricks in the base of the tart with a fork. Place the dough into the freezer and chill for 15 minutes.
Remove the tart shell from the freezer. Drain the excess juice from the berries. Fill the tart shell with the berry mixture. In a small bowl, crumble the butter into 1/3 cup oats and 1 tbsp flour. Sprinkle onto the tart.
Place the tart pan onto a baking sheet and into the oven. Bake for 45-50 minutes, until the crust is brown and the filling is bubbly. Remove from the oven and let cool. Place in the fridge overnight, to help the fruit set. Remove the next day and slice. Can be stored in the fridge for 4 days.