Extract juice from the oranges and lemons. Grate the rinds on a piece of waxed paper or in a small bowl. In the top of a double boiler over water just under boiling, beat egg yolks for 1 minute. Add grated orange and lemon rinds and all other ingredients except ice cream and strawberries. Keep beating until mixture attains the consistency of Hollandaise sauce and foams up a bit. Remove from heat. Make individual strawberry sundaes and liberally top with the sauce.