Preheat the oven to 190°C.

Place the pears in a baking dish with the granulated sugar and bake for about 10-15 minutes, until the fruit starts to soften and release its juices. Add the blueberries, bake for 5 more minutes and remove from the oven.

Meanwhile, place the flour, butter, and a pinch of salt into a large bowl. Rub together with your fingertips until the mixture resembles coarse breadcrumbs. Add the pistachios and brown sugar, then stir to combine.

Sprinkle the crumble mixture evenly over the fruit in the baking dish and bake for 30–35 minutes, until golden and bubbling. Serve warm with ice cream if desired.