Long strips of raw zucchini and shaved fennel absorb the lemony vinaigrette, making a delicious base for this salad. Serve right away after tossing with the dressing to keep the zucchini crisp.
Very thinly slice zucchini lengthwise into long strips with a vegetable peeler, mandoline or knife. Place the strips on a double layer of paper towel and let stand while you prepare the rest of the salad.
Very thinly slice fennel bulb with a knife or mandoline. Chop enough fronds to equal about 1/4 cup. Whisk oil, lemon juice, salt and pepper in a large bowl. Add the zucchini, fennel, fronds and onion; gently stir to coat well. Serve sprinkled with cheese.