1 lb. headless large shell-on shrimp (26 to 30 per lb.)
1 1⁄4 tsp. kosher salt
1 cup water
1 3⁄4 lbs. vine-ripened tomatoes (about 5 tomatoes)
6 oz. fresh hot pork sausage, casings removed
1 large white or yellow onion, chopped
3 cloves garlic, finely chopped
1 large poblano chile, seeded and diced (about 1 cup)
1/2 tsp. freshly ground black pepper
1/2 tsp. smoked paprika
1/2 tsp. crushed dried red pepper flakes
1 Tbs. red wine vinegar
Peel the shrimp and throw the shells into a small saucepan set over medium heat. Add one cup water and a quarter teaspoon of the salt and simmer until reduced by half, five to six minutes.
While the shrimp stock simmers, core the tomatoes: Set a strainer over a medium bowl. Cut the tomatoes in half crosswise and, using your pinkie finger, tease the seeds out of the cavities of each half, letting them fall into the strainer. Tap the rim of the strainer against your palm for 30 seconds, until most of the flavorful gel clinging to the seeds dissolves and drips into the bowl. Discard the seeds. Chop the tomatoes; you should have two cups. Add them to the bowl with the tomato water.
Place the sausage into a heavy-bottomed four-quart Dutch oven or pot set over medium-high heat, and cook, stirring and breaking up the sausage with a wooden spoon, until the pork is just browned and has rendered some fat, about six minutes. Add the onion, garlic, poblano, remaining teaspoon of salt, black pepper, paprika, and red pepper flakes. Cook, stirring and scraping up the browned bits on the bottom of the pan as the peppers and onions release their liquid, until the peppers and onions have softened, about six minutes.
Add the tomatoes and their juice and the strained shrimp broth, turn the heat to high, and cook until the tomatoes have completely collapsed into a red, bubbling stew, six to eight minutes. Remove the pot from the heat and stir in the shrimp and vinegar. Cover and let stand for three minutes, until the shrimp are cooked through.