Cook macaroni according to instructions on pack, drain and rinse.
Boil, peel and cut potato in 1/2 " cubes. Chop celery. Peel
and slice the eggs. Mix all these together, toss in salt and pepper
to taste and keep aside.
To make mayonnaise: break the egg into the liquidiser jar of the
mixer, add salt, pepper, sugar, mustard and vinegar,
Run the mixture for a few seconds on high speed.
With the mixture still running, pour the oil in a thin stream.
Turn off mixer. Pour out the mayonnaise into a bowl and whisk in
the cream cheese. Add the salad mixture and mix thoroughly. Taste
and correct the seasoning.
Serve decorated with lettuce leaves and tomato slices.