Bring a good amount of water to boil in a large pot.
While it is heating, add a generous amount (6 to 8 tablespoons) of the boil seasoning to the water and set a large bowl of half ice/half water near the sink.
When the water is at a rolling boil, add the shrimp and cook for 3 minutes . . . no more!
Drain in a colander and then immediately place them in the ice bath. (This will 'shock' them and keep them from overcooking and turning tough.)
When the shrimp have cooled, drain them, then peel and devein them.
Finely dice the shrimp, putting them in a medium bowl.
Add the onion, then add the mayonnaise, mixing them thoroughly with the shrimp.
Hit the mixture with a few dashes of Tabasco and salt and pepper to taste.
Refrigerate until ready to serve.
