In a medium-size bowl, combine the first 6 ingredients (lime juice through sea salt and freshly ground pepper) to make dressing and set aside.
On a large cutting board, pat the shrimp dry with a paper towel and season lightly with sea salt and pepper.
In a large skillet on medium-high heat, cook the shrimp for 2 minutes per side or until cooked through. Allow to cool on a cutting board for 3 minutes and then chop.
Add the next 3 ingredients (avocado through sesame seeds) and shrimp to the bowl with the prepared dressing. Fold the ingredients together to combine. Serve immediately on butter lettuce leaves.