Avocado, Fennel, and Citrus Salad
1. Grate 1/4 tsp. zest from orange; set aside. Peel orange and grapefruit; remove pith. Using small, sharp knife and working over bowl to catch juice, cut between membranes of fruit to release segments.
2. Whisk together vinegar, fennel seeds, salt, reserved 1/4 tsp. orange zest, and 1 Tbs. juice from orange and grapefruit in small bowl. Gradually whisk in oil. Season with salt and pepper.
3. Place 1 avocado half on each of 4 plates. Drizzle 1 tsp. dressing over each. Toss sliced fennel, sprouts, and shallots with enough remaining dressing to coat. Spoon fennel mixture atop avocado halves, mounding and overflowing slightly. Arrange reserved grapefruit and orange segments around avocados. Drizzle more of remaining dressing over orange and grapefruit segments.