Form into a ball, dust with flour, and flatten into a disk, wrap in plastic wrap and refrigerate until firm, at least 1 hour (or freeze for 30 minutes). Or leave in a ball and refrigerate overnight (this is what i always do).
Place the sliced rhubarb and strawberries in a large mixing bowl. In a separate bowl, whisk together the flour, both sugars, cinnamon, ginger and orange zest. Pour the flour mixture over rhubarb and toss until evenly coated. Drizzle with orange juice and toss again. Set aside.