500g mixed berries and currants, such as raspberries, blackberries, blueberries, redcurrants or blackcurrants
ice cream or custard, to serve
Heat oven to 200C/180C fan/gas 6. Put the flour, oats, butter and sugar in a bowl, squash together with your fingers into a crumble texture, sprinkle over a baking tray and bake for 10 mins, stirring and roughly breaking up halfway through cooking. Can be done up to 2 days ahead, and stored in an airtight container.
Meanwhile, put the strawberries, sugar and cornflour in a large pan. Stir together and set over a medium heat. Cook until the strawberries just start to release their juices and soften, then stir in the remaining berries. Transfer to an ovenproof baking dish.
When the crumble topping is cooked, sprinkle it over the fruit, and place back in the oven for a further 15 mins until bubbling and golden. Leave for 5 mins before serving with ice cream or custard.