In small saucepan, stir together egg yolks, vinegar, water, sugar, mustard, salt and
pepper until thoroughly blended. Cook over very low heat, stirring
constantly, until mixture bubbles in 1 or 2 places. Remove from heat. Let stand 4 minutes.
Pour into blender container. Cover and blend at high speed. While blending, very slowly
add oil. Blend until thick and smooth. Occasionally, turn off blender and scrape down
sides of container with rubber spatula, if necessary.
Cover and chill if not using immediately.
about 1 1/4 cups