Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
750       milliliter    rhubarb, cut in 5 cm pieces OR 1 package (600 g) frozen, thawed
25        milliliter    water 
175       milliliter    sugar 
5         milliliter    vanilla 
                        Red food coloring (optional) 
1                       egg white

Preparation:

Puree rhubarb with water. Add sugar and cook until rhubarb is tender (about 5 min), stirring frequently. Remove from heat; add vanilla and food coloring. Cool to room temperature. Beat egg white until stiff but not dry. Fold into rhubarb mixture. Pour into 2.5 L baking dish (23 cm square). Freeze until firm around edges (about 1 h). Turn into chilled bowl; beat until smooth. Freeze partially (about 1 h more); beat again. Freeze until firm (about 2 h more).