How to Make It
Preheat the oven to 375°. Spread the hazelnuts in a pie plate and toast until they are fragrant and the skins blister, about 14 minutes. Transfer the toasted hazelnuts to a kitchen towel and let cool slightly, then vigorously rub the nuts together to remove the skins. Coarsely chop the nuts.
In a large bowl, whisk the Champagne vinegar with the Dijon mustard, honey and minced shallot. Add the extra-virgin olive oil and whisk until blended. Season the vinaigrette with salt and freshly ground black pepper. Add the arugula, pea shoots, radishes, fennel and chopped hazelnuts and toss well. Season with salt and pepper and serve right away.