In a food processor jar, break the egg. On the lowest speed, whisk the egg for 30 seconds.
Gradually add the salad oil to the egg. Beat the mixture till it begins to thicken.
Now add the juice of one lemon, 2 tsp sugar, 1 tsp salt and freshly ground black pepper and whisk for 1-2 minutes till the sugar granules have dissolved. Transfer to a glass jar to store in the refrigerator. The mayonnaise will stay in the refrigerator for up-to one month.
Flavored mayonnaise can be made by adding mustard, garlic, wasabi, barbeque sauce after the mayonnaise has thickened.