Ground flaxseed contributes a nutty flavor, as well as omega-3 fatty acids, to salad dressings. The flaxseed mixture thickens as it stands and gives the dressing its texture. Try tossing it with romaine lettuce, Parmesan cheese shavings, and toasted bread cubes for a classic Caesar salad.
Place the flaxseed in a clean coffee grinder or blender, and process until finely ground. Place flaxseed meal in a medium bowl; add water, stirring with a whisk. Let stand 5 minutes. Add vinegar and remaining ingredients; stir with a whisk.
Note: Store dressing in an airtight container in the refrigerator for up to 2 days. Store remaining flaxseed in the refrigerator; since it's high in fat, it can go rancid easily.