Heat cream, milk and sugar in heavy saucepan, stirring until sugar dissolves. Add egg yolks by adding some mixture to eggs to dilute, and then adding diluted eggs to rest of pan (adding straight will cook them and make for lumpy cream). Whisk constantly over med heat until mixture coats the back of a spoon (seems to take forever, about 10 min?). DO NOT LET BOIL (or it will curdle) Strain, if you want, and add vanilla (I never strain, it comes out fine). Cool completely in refrigerator. Freeze according to manufacturers instructions. Makes about 1 quart. ( I double this if using the hand crank - it has a much larger capacity, but doesnt seem to last any longer after its made.... Hmmm....)