In a food processor place the onion, grated ginger, celery, carrots and garlic and puree until the vegetables are fine and grainy but not pureed.
Add the vinegar, water, ketchup, soy sauce, agave, lemon juice, salt, pepper and optional miso paste. Pulse a few times to mix the ingredients.
With the processor running, add the oil in a steady stream then stop. The mixture should be loose but be a bit grainy.
Enjoy over a simple iceberg and tomato salad.
