Crumble has to be one of the easiest desserts to prepare and it is extremely easy to adapt, using whatever fruit is in season. You can also vary the ingredients for the crumble mix itself; I sometimes use wholemeal flour and nuts, but I'm a complete stickler for using jumbo oats as they really give the dessert a crunchy, nutty texture. This crunchy rhubarb and strawberry crumble makes the best of fantastic, in-season Irish produce and is pure simplicity with phenomenal results. Serves four. For