Eugenia Bone, prolific home cook, writer and author of Well-Preserved, serves this simple green salad with a cheese plate and plenty of rustic bread. She always includes Taleggio and aged Parmigiano-Reggiano, as well as fresh imported sheep's-milk ricotta whenever she can find it at the market.
In a large salad bowl, whisk together the chopped shallot, lemon juice and mustard. Gradually add the oil, whisking constantly, until the vinaigrette is emulsified and creamy-looking. Add the baby arugula and sliced fennel to the salad bowl, season the salad with salt and black pepper and toss well. Serve.