Crisp romaine, juicy fennel, and luscious avocado make a delicious team in this beautifully shaded all-green salad. To boost the mild anise flavor of the fennel, we've added fresh tarragon leaves and a tarragon vinaigrette. The result: an incredibly fresh-tasting salad that's full of healthy ingredients.
To make the vinaigrette, place all the ingredients in a small glass jar and seal the lid tightly. Shake vigorously to combine, and set aside. Shake again just before dressing the salad. The vinaigrette is best at room temperature; it will keep, refrigerated, for up to 1 month.
To assemble the salad, place the romaine, fennel, and tarragon in a large bowl and toss to combine. Add the vinaigrette to taste and toss again. Transfer the salad to a platter or divide among salad plates. Garnish with the avocado and pass more vinaigrette on the side.