Make the dressing by adding 1 at a time through the feed opening of a running blender, vinegar, parsley, marjoram, garlic, salt, and pepper. Leaving the blender running, pour in the olive oil in a slow stream. Set aside briefly.
Combine the spinach, carrots, radishes, and celery in a large bowl and add enough dressing to coat. Serve family style with additional dressing on the side.
2007, Robert Irvine, All Rights Reserved