-Preheat oven to 350 degrees.
-In a small bowl, combine rhubarb, apple, granulated sugar and cinnamon. Pour fruit mixture in a 9" pie pan.
-In bowl of a food processor, combine flour, oats, brown sugar, butter, flaxseed meal, nutmeg and nuts, if desired. Process until mixture resembles coarse sand. Sprinkle on top of fruit. Bake 25 to 30 min, until filling is bubbly and topping is browned.