Boil shrimp in water, to cover, with shrimp seasoning just until pink. Drain and reserve the shrimp boil water. Chop shrimp into bite-size chunks, put on paper towels; set aside to cool. In the reserved water, boil the rice according to package instructions until tender, drain and set aside. Add the onion, olives, and black pepper, to taste, to the rice. Then stir in the mayonnaise. Add the cooled, dry shrimp last. Toss and serve.