This duo of ingredients is great baked in a pie. Why wouldn't it be good frozen into sherbet? This recipe comes from the Williams Sonoma Kitchen Library.
2 tablespoons water
1 teaspoon unflavored gelatin
1 package (1 pound) frozen unsweetened sliced rhubarb, thawed
1 package (1 pound) frozen unsweetened whole strawberries, thawed
1 1/2 cups sugar
1 1/2 cups whole milk
1/2 cup light corn syrup
Pour the water into a small cup. Sprinkle the gelatin over the water. let stand for 10 minutes to soften.
Meanwhile, in a large, heavy saucepan, combine the thawed rhubarb and strawberries with their juices and the sugar. Place over medium heat and stir till the sugar dissolves, about 3 minutes. Continue cooking, stirring occasionally, until the rhubarb is tender, about 5 minutes.
Add the gelatin mixture to the hot rhubarb mixture and stir until the gelatin dissolves, about one minute.
In a food processor fitted with the metal blade or in a blender, puree the rhubarb mixture until smooth. Pour the puree into a large bowl. Add the milk and corn syrup and stir to blend. Refrigerate until cold, about one hour.
Transfer the sherbet mixture to an ice cream maker and process according to the manufacturer's instructions. Transfer the sherbet to a container. Cover and freeze until firm, at least 4 hours or up to 3 days. Makes about 5 cups.