Pre-heat oven to 180°C / 350°F / Gas Mark 4
Chop up the fruit and stew in a pan until soft (this should take about 10 minutes)
Pour the fruits into a deep ovenproof dish
Make the crumble by rubbing together the butter and flour until it resembles breadcrumbs. Then rub in the sugar
Sprinkle the crumble on top of the fruit and bake in the oven for 25 minutes