Bring a large pot of salted water to a boil. Add the shrimp and cook for 2-3 minutes until they turn pink and start to float. Transfer the shrimp to an ice bath, peel, and roughly chop.
Combine the mayonnaise, cilantro, lime juice, garlic, ginger, and salt in a large bowl and mix well.
Add the pineapple, red pepper, green onions, and shrimp to the bowl and gently toss. Serve over lettuce.