Ingredients
4 pounds ripe tomatoes, preferably beefsteak, cut into chunks
1 tablespoon coarse salt
12 ounces (about 18) large shrimp, peeled and deveined, tails on, shells reserved
4 cups cold water
1 teaspoon red-wine vinegar
1/2 teaspoon sherry vinegar
1/2 cup Madeira or dry sherry
18 mussels, scrubbed well and debearded
3 garlic cloves, smashed
Extra-virgin olive oil, for drizzling
1 tablespoon very thinly sliced fresh flat-leaf parsley, for garnish
1 three-inch piece English cucumber, peeled, seeded, and finely diced, for garnish
1/2 yellow bell pepper, ribs and seeds removed, finely diced, for garnish
Preparation
Working in batches, pulse tomatoes and salt in a food processor until coarsely chopped. Transfer mixture to a cheesecloth-lined sieve set over a stockpot. Let strain in refrigerator for at least 6 hours (or up to overnight).
Bring shrimp shells and 3 cups water to a boil in a saucepan. Reduce heat, and let simmer, partially covered, for 30 minutes. Strain through a fine sieve into a heatproof bowl; discard shells. Refrigerate until chilled, at least 1 hour (or up to 1 day).
Extract remaining juice from tomatoes by gently squeezing cheesecloth, being careful not to extract solids. Add shrimp stock and vinegars to juice. Refrigerate until chilled, at least 1 hour (or up to 1 day).
Bring Madeira and remaining cup water to a simmer in a 12-inch skillet over medium-high heat. Add shrimp, mussels, and garlic. Cover, and let simmer until shrimp have cooked through and mussels have opened, about 3 minutes. Using a slotted spoon, transfer shrimp and mussels to a large bowl (discard any unopened mussels). Let cool, about 10 minutes. Divide chilled broth among 6 shallow bowls. Drizzle with oil, top with shrimp and mussels. Garnish with parsley, cucumber, and bell pepper just before serving.
