A dash of cayenne pepper in the vinaigrette gives this brightly flavored salad a little kick.
In a salad bowl, toss together the fennel, celery, radishes, and orange segments.
Whisk together the orange juice, sherry vinegar, olive oil, salt, sugar, and cayenne. Pour over the salad and toss to combine. Serve, or cover and store in the fridge until ready to serve.