This is one of my absolute favorite desserts. It's a little tart, which I think is just perfect.
3-4 cups rhubarb, sliced 1" thick
1/2 cup sugar
3 tbsp flour (or rice flour)
In large bowl, combine all ingredients. Let sit in fridge for 1 hour. Pour into 1 double crust pie shell and top with lattice crust or crust with vents. Bake at 400 degrees for 50 minutes.