Mayonnaise Cost: 0.5€
1 yolk of egg
1/2 teasp. of mustard
1/4l of vegetable oil
pinch of salt and pepper
few drops of lemon juice
The First Rule to success the mayonnaise is: All the ingredients (specially the yolk of egg and mustard) must have temperature of the room. Never do the mayonnaise with products just exit prom the fridge.
In the medium bowl put the yolk of egg, mustard and salt. Start to mix with the spoon from wood or whisk.
And then little by little add the oil and continue to mix.