For Lime Dressing, remove 1 tsp. zest from lime; juice to get 3 tablespoons In a small bowl combine zest, juice, cayenne, and ¼ teaspoon of the kosher salt. Slowly whisk in 2 tablespoons of the olive oil until combined.
In a medium bowl toss shrimp with the remaining 1 teaspoon oil and the remaining ¼ teaspoon kosher salt. Thread shrimp onto skewers. Grill shrimp on the greased rack of a covered grill directly over medium heat 3 to 4 minutes or until opaque, turning once halfway through grilling.
On a large platter arrange shrimp, avocados, tomato, and onion. Drizzle with dressing and top with cilantro.
