Preheat the oven to 400 degrees.

Place the refrigerated pie crust in a pie pan and crimp the edges if desired. Set aside.

In a large bowl beat the egg. Add in the sugar, flour, lemon juice, rhubarb, and strawberries and tossed until combined. Pour into unbaked pie crust.

In a small bowl combine the ingredients for the crumble using your fingers to cut the butter into the dry ingredients. Sprinkle over top of the strawberry rhubarb mixer.

Bake at 400 degrees for 10 minutes then lower the temperature to 350 and continue baking for 35 minutes or until the crumble is browned and the filling is bubbling.