Shrimp cocktail

Ingredients

10 cups cold water

2 medium carrots, quartered

2 stalks celery, quartered

1 large onion, quartered

1 head garlic, halved

1/2 bunch parsley

5 sprigs fresh thyme

1 pound medium or large shrimp, in the shell, rinsed

1 tablespoon kosher salt

Cocktail Sauce, recipe follows

1 lemon, zest finely grated and juiced

4 teaspoons prepared horseradish, or to taste, drained