Blender Mayonnaise - Joy of Cooking

1 ea egg
1 t dry mustard
1 t salt
dash cayenne
1 t sugar
1 1/4 c vegetable oil
3 T lemon juice

Add egg, mustard, salt, cayenne, sugar and 1/4 cup of oil, and blend on high until thoroughly combined. With blender still running, take off the cover and slowly add 1/2 cup oil then the lemon juice until thoroughly blended. Add slowly the remaining 1/2 cup oil until thick. You may have to stop and start the blender to stir down the mayonnaise.