So... if you've some eggs, olive oil and mustard, why not make your own mayo?
2 egg yolks
1 teaspoon Dijon mustard
1/4 teaspoon cayenne pepper
2 tablespoons fresh lemon juice
1 cup vegetable or olive oil
You could substitute a very small splash of vinegar for the lemon juice, by the way.
1. Combine the egg yolks, mustard, cayenne and lemon juice in a food processor. Start to process, and as the machine runs, add the oil in a thin stream through the top spout. The mayonnaise will come together and thicken all of a sudden.
2. If the mixture is too thick, add a little warm water to thin it. Add salt and pepper to taste. The mayonnaise will keep for about 1 week in the refrigerator.
Et voila... Supper!