Note to self: Next time you make crumble, leave the butter sitting out for half an hour to warm up before trying to cut it into the dry ingredients.
I'm not transcribing the recipe, because it was a simple adaptation (replace half the rhubarb with strawberries) of the Rhubarb Crumble recipe in Rose Elliot's Complete Vegetarian Cuisine, and you should have a copy, whether you're a vegetarian or not. Just trust me on this. It is a veritable fount of information on the basic ingredients, and has many, many good recipes.
ETA: Mmmmmmmmmm.