This pretty combination of colorful ingredients perks up dreary winter days. Juicy jicama, sweet grapefruit, and crisp, anise-flavored fennel partner over baby arugula to create a delicious, refreshing salad that's dressed with a very light vinaigrette. Butter lettuce and watercress will also work well.
Peel and segment the grapefruits, saving the juices that are released in the process. Set aside. (For more details, see our Chef Tips on "segmenting citrus fruit.")
Make the vinaigrette by combining the olive oil, grapefruit and lemon juices, plus salt and pepper to taste in a small glass jar. Shake vigorously to combine.
Add a tablespoon or two of vinaigrette to the sliced fennel, tossing to coat. Set aside.
Add a tablespoon of vinaigrette to the jicama matchsticks and set aside.
Place the mâche in a bowl and add some of the vinaigrette. Toss to coat the greens. Divide the mâche among 4 salad plates. Decoratively arrange the grapefruit segments around the greens. Divide the fennel among the plates, and scatter the jicama on top. Garnish each salad with fennel fronds, if desired, and serve immediately.