1/2 medium head green cabbage, cored, halved lengthwise, and thinly sliced (about 6 cups)
1 green apple, quartered, cored, and thinly sliced
1 medium fennel bulb, halved, cored, and thinly sliced (about 2 cups)
3 oz. trimmed watercress, cut into bite-size pieces (5 loosely packed cups)
1/3 cup chopped toasted pecans
In a small bowl, whisk together the lemon juice and zest, mustard, 1/2 tsp. salt, and 1/4 tsp. pepper. Slowly whisk in olive oil.
Place cabbage, apple, fennel, and watercress in a large serving bowl. Just before serving, gently toss the salad with the dressing. Season to taste with additional salt and pepper, sprinkle the pecans on top, and serve.