Mexican-style shrimp cocktail

Bring water to a rapid boil and add salt a little at a time until heavily salted, like the sea.

Add the shrimp all at once and stir quickly so they cook evenly.

As soon as the water barely returns to the boil, about a minute or a little longer, turn off the heat; reserve a little cooking liquid for the sauce.

If not quite done, cover and let them steam a minute in the residual heat.

Drain the water off, holding the lid.

Put the shrimp into ice water to cool quickly and stop the cooking.

Start the sauce with the ketchup, add the shrimp cooking broth and the lime juice.

Add two to four tablespoons of Mexican hot sauce to taste.

Add the onion, chopped very small and rinsed in a strainer to remove its harshness, and a little chopped cilantro; mix.

Optionally add a little olive oil for mouthfeel.

Cut the avocado around the pit, twist apart, scoop out the flesh and dice small; add to the sauce.

Lift the shrimp out of the ice water, drain in a spider and mix into the sauce.

Spoon into a little dish or sundae glass, top with a few more shrimp, a slice of avocado and cilantro sprigs; serve with tortilla chips or saltine crackers.