For the mayonnaise, add the oil, egg, lemon juice, mustard and salt to the blender that fits the hand blender. Put the hand blender in the beaker all the way to the bottom, until it is in contact with the floor. Turn on the hand blender and slowly pull it up until no more oil can be seen.
For the American dressing, add the ketchup, lemon juice and curry powder to the mayonnaise. Mix with a hand blender and season with salt, pepper and liquid sweetener.
If the dressing is too thick, add 4 - 6 tablespoons of water and whisk.