Ingredients

  • 1/3 cup finely chopped shallot
  • 2 tablespoons finely chopped carrot
  • 2 tablespoons finely chopped celery
  • 1 lb medium shrimp in shells (31 to 35 per lb), peeled, reserving shells, and deveined
  • 1 lb sea scallops, tough muscle removed from side of each and reserved
  • 5 tablespoons unsalted butter, softened
  • 1 teaspoon tomato paste
  • 1 cup dry white wine
  • 3 cups water
  • 1 tablespoon seafood glaze* (optional)
  • 2 fresh flat-leaf parsley sprigs
  • 3 tablespoons all-purpose flour
  • 1 cup heavy cream
  • 1/2 teaspoon fresh lemon juice, or to taste
  • 1 1/2 teaspoons salt
  • 1/2 teaspoon black pepper
  • 2 tablespoons Cognac
  • 1/2 cup finely chopped fresh chives
  • 14 (6- by 3-inch) flat fresh or no-boil lasagne noodles (without curly edges)
  • Special equipment: a 3-quart flameproof rectangular casserole dish (about 13 by 9 inches; not glass)

Method

  • Cook shallot, carrot, celery, reserved shrimp shells, and reserved scallop muscles in 3 tablespoons butter in a 2- to 3-quart heavy saucepan over moderately low heat, uncovered, stirring occasionally, until vegetables are softened and pale golden, about 5 minutes.
  • Add tomato paste and cook, stirring, 1 minute.
  • Add wine and boil over high heat, stirring occasionally, until reduced to about 1/4 cup, 6 to 8 minutes.
  • Add water, seafood glaze (if using), and parsley sprigs and simmer, covered, 30 minutes.
  • Discard parsley and puree stock, including shrimp shells, in 2 batches in a blender (use caution when blending hot liquids).
  • Pour through a fine-mesh sieve into a bowl, pressing on and discarding solids.
  • Melt remaining 2 tablespoons butter in cleaned saucepan over moderately low heat, then add flour and cook roux over low heat, stirring, 3 minutes.
  • Add warm seafood stock all at once, whisking, and bring to a boil, whisking.
  • Add 1/2 cup cream and gently simmer sauce, whisking occasionally, 10 minutes.
  • Stir in lemon juice, 1/2 teaspoon salt, and 1/4 teaspoon pepper.
  • Transfer 1/2 cup sauce to a bowl set in a larger bowl of ice and cold water to cool for filling.
  • Cut one third of shrimp and one third of scallops into 1/4-inch pieces and toss with 1/4 teaspoon salt.
  • Puree remaining shrimp and scallops in a food processor with Cognac, cooled 1/2 cup sauce, remaining 3/4 teaspoon salt, and remaining 1/4 teaspoon pepper.
  • Add remaining 1/2 cup cream and pulse just until combined.
  • Transfer mousse to a large bowl and stir in shrimp and scallop pieces and chives.
  • Preheat oven to 375F.
  • Boil lasagne noodles a few at a time in a large pot of boiling salted water , stirring to separate, until al dente, about 2 minutes for fresh noodles or about 6 minutes for no-boil.
  • Gently transfer noodles with tongs and a slotted spatula to a large bowl of cold water to stop cooking, then lift out, shaking off water, and lay flat on dry kitchen towels (not terry cloth).
  • Spread 1/3 cup mousse over each noodle, leaving a 1/2-inch border on both short ends.
  • Starting with a short end, loosely roll up each noodle.
  • Spread about 1/2 cup sauce on bottom of casserole dish and arrange cannelloni, seam sides down, snugly in 1 layer over sauce.
  • Pour remaining sauce over cannelloni and bake, covered with foil, in middle of oven until sauce is bubbling and filling is just cooked through, 25 to 30 minutes.
  • (To test filling for doneness, insert a metal skewer into a cannelloni and hold it there 5 seconds.
  • Remove skewer and press it against your bottom lip: If metal is warm, casserole is hot all the way through and filling is cooked.)
  • Preheat broiler.
  • Remove foil and broil cannelloni about 3 inches from heat until brown spots appear, 3 to 5 minutes.
  • Let stand 10 minutes before serving.
  • Available at some supermarkets, specialty foods shops, and More Than Gourmet (800-860-9395).