Using a mandoline, shave the fennel bulb paper-thin to maximize surface area for the dressing. Chop the fennel fronds separately and set aside. Cut the celery stalks into 1/4-inch slices on a slight bias—this creates more visual interest and helps them absorb the vinaigrette. Peel the cucumber and slice it into 1/4-inch moons. I find that peeling cucumber prevents any bitterness from the skin and gives the salad a more refined appearance. Keep all vegetables separate until ready to dress, as this prevents them from releasing excess liquid too early.

In a small bowl, whisk together the lemon juice and salt first, allowing the salt to dissolve slightly into the acid. Then slowly whisk in the olive oil to create an emulsion—the high-quality peppery olive oil you use here really matters, as it's the star of the dressing in such a simple recipe. The emulsification helps the dressing coat the vegetables evenly rather than pooling at the bottom of the bowl.

Add all the prepared vegetables from Step 1—including the fennel fronds—and the fresh dill to the vinaigrette. Toss gently but thoroughly to coat everything evenly. I like to let the salad sit for just 2-3 minutes before serving so the vegetables can absorb some of the dressing while still maintaining their crisp texture. Serve immediately for the best crunch and freshness.