To prepare the skinny spiralized salad, peel the carrots. Using the spiralizer or julienne peeler, make noodles out of the carrot, zucchini and cucumber.
Spiralize the onion. Or cut into very thin slices and separate out into thin segments.
Place the prepared vegetables along with lettuce in a large bowl and toss well in the olive oil so that it uniformly coats all the ingredients.
Slake the mustard and salt in the lemon juice in a small cup and pour it over the salad, gently tossing with fingertips so that it covers the entire salt.