Combine tomato and water in a small bowl; cover and let stand 15 minutes.
Drain; coarsely chop tomato, and set aside.
Holding cucumber in one hand, run a citrus stripper or vegetable peeler lengthwise down the sides of cucumber to create strips about every 1/2 inch, if desired.
Thinly slice cucumber.
Combine cucumber, tomato, spinach, onion, and mushrooms; toss gently.
Arrange salad evenly on individual salad plates.
Drizzle Creamy Italian Dressing evenly over each salad.