Seafood in tomato sauce has a long history in Neapolitan cooking. In fact, marinara sauce is named for the mariners who supposedly created it. As mussels were plentiful and cheap in both Italy and America, my grandparents made this at home often. We serve it at the restaurant, too, usually over linguine as a pasta or main course. As an antipasto, serve it with crusty bread… but I didn’t really have to tell you that, did I? — Sal Scognamillo, Patsy’s Italian Family Cookbook.
For mussels marinara with linguine: Use 3 cups tomato sauce, ¼ cup dry white wine, and ¾ cup cooking liquid. Boil until reduced to about 3 ½ cups, about 5 minutes. Use as a sauce for 1 pound cooked linguine. Top each serving with mussels.
Put the mussels in a large pot and add the water. Cover and bring to a boil over high heat. Cook just until the shells open, about 5 minutes. Using a slotted spoon, transfer the opened mussels to a colander, discarding any unopened mussels. Reserve the cooking liquid.
Line a wire strainer with moistened paper towels and set over a medium bowl. Strain the cooking liquid through the strainer. Measure and reserve ½ cup of the strained liquid. (You can cool, cover, and freeze the remaining mussel cooking liquid for another use or as a fish stock.) Wash and dry the pot.
Bring the reserved cooking liquid, the tomato sauce, wine, parsley, and oregano to a boil over high heat. Cook, stirring often, until reduced to 2 cups, about 5 minutes. Add the mussels, cover, and cook until the mussels are reheated, about 3 minutes more. Season again with salt and pepper. Divide the mussels and sauce evenly among four soup bowls. Serve hot, with the toasted bread.