Mixed Summer Berry Crumble

approx 2lbs of mixed berries (strawberries, raspberries, blueberries etc)
1 1/2 cup of flour
250 gr of butter
1/2 cup brown sugar

(these measurements are approx as I don't tend to actually measure the ingredients when I do this, it's more touch/sight oriented for me)

Preheat oven to 400F
Place the berries into a metal baking dish, arrange as you wish
Add other ingredients to a bowl & rub the butter into the mixture with your fingers until you obtain a fine breadcrumb like consistency
Sprinkle over the top of the berries
Place into the oven for approx 30-40 mins or until golden brown on top