2 c. rhubarb, cut fine
2 eggs and fill the cup with milk (Half and Half or evaporated milk)
2 tbsp. flour
1 1/2 c. sugar

Mix sugar, flour and rhubarb, then mix in egg and milk. Put into unbaked pie shell and bake at 425 degrees for 15 minutes, then reduce heat to 350 degrees for 25-30 minutes.