In a stand mixer on a medium speed or by hand with a whisk, beat the the egg yolks with two tablespoons lemon juice and the dijon, until light and frothy. Tip: If you don’t have an electric mixer, wrap a dampened kitchen towel around the bowl so it’s stabilized. Now you have an extra hand to drizzle oil without having to hold the bowl in place.
Begin adding the oil slowly, whisking continuously to incorporate before adding more. Tip: Use a measuring cup with a pour spout to add the oil. If you add oil too quickly or add more before it incorporates, it can break. Once the oil and egg emulsify you can add the oil a little more quickly. The mayonnaise should gradually become a pale yellow and begin to stiffen.
You’ve reached the desired consistency when small peaks form but then fold over. Tip: Add a teaspoon or two of water if it’s too thick, i.e peaks are forming easily and don’t fold. If the mayonnaise is not thick enough, i.e doesn’t peak at all, whisk in more oil.
Taste and then season the mayonnaise with salt and additional lemon juice as desired. Homemade mayonnaise should be used within 4-5 days, store in a very clean covered container in the refrigerator.