Combine first 6 ingredients in a large bowl; pour Citrus Vinaigrette over shrimp mixture, and gently toss to combine. Cover and chill 4 to 24 hours.

Place lettuce on a platter. Spoon shrimp mixture over lettuce, reserving vinaigrette. Drizzle with reserved vinaigrette. Top with avocado.

Citrus Vinaigrette

1/4 cup fresh orange juice

1/4 cup olive oil

1 tablespoon country-style Dijon mustard

1 tablespoon fresh lemon juice

1/4 teaspoon salt

1/8 teaspoon freshly ground pepper

Whisk together orange juice, olive oil, Dijon mustard, lemon juice, salt, and pepper.