Hands down, homemade mayonnaise is superior to store-bought. Luckily, it's easy to make with an immersion blender and a wide-mouth, tall canning jar. Make it once and you will be hooked!
In a large-mouth, tall canning jar, add the egg yolks, lemon juice, Dijon mustard, salt, and pepper. Process with an immersion blender for 5 to 10 seconds.
With the immersion blender running, add the oil in a slow, steady stream. Process until smooth, thick, and creamy. Taste for seasoning.
Mayonnaise may be refrigerated for up to made 3 days.