Place all ingredients in a blender and blend until smooth. If the dressing is too thick, add a teaspoon of water at a time and blend again (but keep in mind that this type of dressing should remain fairly thick). Toss with shredded Romaine lettuce for a Caesar salad base to which you can add desired toppings, or use as a dip with raw vegetables. Leftover dressing will keep, covered, in the refrigerator for up to 3 days.