So, I looked for recipes online and found a wonderful, super-dooper recipe. It is located here. It has a special secret, the sugar/flour part of the recipe is placed, half on the bottom crust and half on top of the rhubarb right before the crust goes on. This makes the bottom crust kind of sugary crisp. The juice from the rhubarb gets to the bottom a bit later in the cooking process so it doesn't get soggy.