1/4 level tsp. mustard (dijon, yellow, whatever you want)
1 tbsp vinegar, lime juice or lemon juice
1 c. oil (extra virgin light olive oil, veggie oil, etc)
2 fresh basil leaves
1 pinch white pepper
Mix all ingredients except for 3/4 cup of oil in a blender or food processor for about 4-5 minutes. As it begins to resemble whipped cream in consistency begin pouring in a steady stream of the remaining 3/4 cup of oil. In about 10 minutes it should be very thick with a minty green color. Let sit covered with plastic wrap or a paper towel at room temperature for 1 hour minimum before storing in the refrigerator.
Note: Changing oil types and mustard types changes flavor. You can always mix in new herbs for a wonderful new flavor on your sandwiches!