Here you go, this is a variation on what is served in Japanese restaurants.
1 cup carrots
1/2 cup onion
1/4 cup celerey
1/4 cup Seasoned Rice Vinegar
1/8 cup light (not lite) soy sauce
1 teaspoon fresh ginger
Throw everything in the blender and blend until smooth, you may have to add a little water depending on water content on your veggies. You may also play with the vinegar and soy amounts, I like a little more vinegar.