Boil the diced rhubarb in a half-cup of water until it is tender. This should take about 10 to 15 minutes. While continuing to cook add 1 cup of sugar to the rhubarb, stir until the sugar is dissolved. Remove the mixture from heat and add corn syrup, orange juice, lemon juice and lemon rind. Turn the mixture into a chilled bowl and place in the refrigerator to cool.
Beat the egg whites, 2 tablespoons of sugar and 1/4 teaspoon of salt until foamy. Slowly add the chilled rhubarb syrup to egg whites. Whisk together until well combined. Pour solution into an ice cream freezer and rotate the freezer as you would if you were making homemade ice cream. Transfer the firm sorbet into a container and place in the freezer.
If you do not have an ice cream maker, pour the solution into a shallow dish and freeze until sherbet is frozen around the edges. Remove from freezer, mix until smooth and refreeze until almost solid. Repeat this process two more times.
While the sherbet is freezing you can make the strawberry sauce. Place 2/3 of the washed and hulled strawberries and 2 tablespoons of sugar in food processor or blender. Puree the strawberries, adding water if necessary, until smooth but not too runny. Slice the remaining strawberries and fold into sauce.
Just before you are ready to serve the sherbet, stir it briefly with a spoon to make it creamy. Serve cold, topped with the strawberry sauce.