1. Place the peppercorns on a double layer of cheesecloth. Gather edges of cheesecloth together, and tie securely. Combine cheesecloth bag, water, salt, red pepper, and lime quarters in a Dutch oven. Bring to a boil; cook 2 minutes. Add shrimp; cook 2 minutes or until done. Drain. Discard cheesecloth bag and lime quarters.
2. Combine shrimp, cilantro, lime juice, and jalapeño pepper, tossing well to coat. Heat tortillas according to package directions. Spoon 1/3 cup shrimp mixture into each tortilla; top each taco with 1 tablespoon tomato, 2 teaspoons sour cream, and 2 teaspoons onions.