In this exact order, add the egg, vinegar or lemon juice, salt, mustard, honey, pepper and oil to the immersion blender cup. Let the ingredients sit for one minute, as the egg yolk settles to the bottom.
Place the immersion blender into the cup and starting slowly pulsing the mixture. In a few seconds you will see the mayo begin to form at the bottom. You can move the immersion lightly up and down to finish. The whole process should take no more than one minute. Add the sour cream. Mix again briefly. Scrape mayonnaise into a container; cover tightly and store in refrigerator for up to one week.
* Wasabi Mayonnaise: Add 1 teaspoon of powdered wasabi (Japanese horseradish) per 1/2 cup of light mayonnaise.
* Mango Mayonnaise: Blend 1/2 cup of light mayonnaise with a cup of mango pieces.
* Garlic Mayonnaise: Stir a teaspoon of crushed or minced garlic and 1/2 teaspoon of dry mustard into a cup of light mayonnaise.
* Tahini Mayonnaise: Whisk 1 tablespoon each of lemon juice and tahini (sesame-seed paste) into 1/2 cup light mayonnaise.
* Chutney Mayonnaise: Blend 1/8 cup of chutney and 1/2 teaspoon each of curry powder and lime juice with 1/2 cup light mayonnaise.
* Sun-Dried Tomato Mayonnaise. Stir 1/8 cup finely chopped sun-dried tomatoes into 1/2 cup light mayonnaise.
* Pesto Mayonnaise: Stir 1 1/2 tablespoons pesto into 1/2 cup light mayonnaise.
* Dijonnaise: Stirring 1 1/2 tablespoons of Dijon mustard into 1/2 cup light mayonnaise.