Bitter Greens, Grapefruit, and Avocado Salad

Remove peels and piths from grapefruits with a sharp knife. Working over a bowl to catch juices, carefully cut between membranes to remove whole segments. In a bowl, whisk together 2 tablespoons grapefruit juice, vinegar, mustard, 1/4 teaspoon salt, 1/4 teaspoon pepper, and yogurt. Slowly drizzle in oil, whisking until combined.

Toss together greens and basil; divide evenly among 4 plates. Top with grapefruit and avocado. Drizzle with vinaigrette, sprinkle with poppy seeds, and serve.