In heavy saucepan, scald milk and half and half with sugar.
Add broken chocolate; stir frequently until chocolate completely melts and thickens slightly.
(Mixture must be quite hot.) Beat egg yolks with salt until very thick.
With wire whip, stir chocolate mixture quickly while adding yolks slowly.
Add liqueur; stirring gently, cook 2-3 minutes until pudding thickens.
Pour into small pots de creme cups or glass dishes.
Cover and chill.