I like making mayonnaise, there is something incredibly satisfying about turning two egg yolks, seasoning and oil into an unctuous, wobbly bowl of deliciousness. People might try to scare you out of making it- not only can it curdle, but it has raw egg yolks in it. Ignore any naysayers, and make something that's worth dipping your frites into.
This is a classic recipe, no innovation or twists on my part. I wouldn't dream of it.
Approximately 250ml groundnut oil
2 eggs yolks only
1 garlic clove, crushed
1 heaped tsp mustard powder
1 level tsp fine salt
freshly ground pepper- white if you want to avoid black specks
1 tsp white wine vinegar
Combine the egg yolks, garlic, salt and pepper in a small mixing bowl. Give them a whisk to combine them. Drop by drop, add the oil, whisking as you go. Go cautiously at first, make sure each addition of oil has been combined into the egg mixture before the next. Soon your mixture will stiffen, so add the vinegar. Now you can relax slightly, and pour the oil in a thin stream into the eggs with one hand, whisking with the other. When all the oil is added (more or less, depending on how you like it), taste, and adjust the seasoning according to your taste.