2 1/2 tablespoons apple cider vinegar
2 tablespoons fresh lemon juice
1/2 tsp sea salt
1.5 tablespoons extra-virgin olive oil
1 1/2 tablespoons coarsely chopped fresh tarragon
2 celery stalks
1 fennel bulb
1 tablespoon chopped fennel fronds
1 small firm, crisp apple (like Pink Lady, or Granny Smith)
Kosher salt and freshly ground black pepper
Garnish with toasted walnuts
Whisk first 3 ingredients in a medium bowl, once the salt is dissolved add the oil and mix well and then add the tarragon. I like a tart dressing so add more oil if you find this too tart and adjust the salt to taste.
Slice celery, fennel and apple with a mandolin (or thinly slice) and chop fennel fronds; toss in dressing to coat. Season to taste with salt and pepper. I like to add toasted nuts.