When we run out of something it is not cost effective to just run into town to pick some up. Yesterday, while making chicken salad, we ran out of mayo which prompted us to try our hand at homemade.
An egg, 1/2 tsp salt, 1/2 tsp mustard, 1/4 cup oil and 1 Tbsp lemon juice. Whirl these in the blender for a few seconds to mix.
Add 3/4 cup of oil in a slow drizzle. Using a blender is great because it has a removable piece on top to add ingredients. No blender? You can do the same thing using a whisk. You can hear the whine of the blender change as the emulsion of egg and oil begins to form.
You might be wondering what the difference is between salad dressing (like Miracle Whip) or salad cream and mayonnaise. Salad dressing uses less egg yolk and oil instead substituting corn starch, corn syrup, vinegar and water. It became popular in the 1930's because it was less expensive as it is made with cheaper ingredients.