For the herb-infused pasta sheet:
Knead the flour with the blended egg yolk and the extract of lagoon herbs until a smooth, harmoniously green dough is achieved. Envelop in film and let it rest for 30 minutes. Subsequently, roll the pasta into a thin sheet and fashion rectangles (approximately 8-10 cm wide).

For the mollusks and seafood:
In a spacious casserole, coax the mussels and lupin clams to open with a thread of oil, the clove of garlic, and the white wine. Shell the mollusks, reserving a few intact bivalves for the final adornment. Carefully filter and preserve all the precious cooking liquor. In a pan with a thread of warm oil, sear the cubed cod and trimmed prawns for 2 minutes, then set them aside alongside the mollusks.

For the velouté and the filling:
In a small saucepan, prepare the foundation of the velouté by combining oil and flour (the roux); introduce the seafood broth along with half of the filtered mollusk nectar, whisking gracefully until a silky, bound sauce emerges. Cook the egg linguine in lightly salted water, drain them whilst still firm (molto al dente), and dress them with the velouté, the prawns, the cod, the mussels, and the lupin clams.

For the linguine cannelloni and the gratin:
Upon each rectangle of green pasta, arrange a portion of the dressed linguine and roll them to fashion elegant cylinders. Slice these cylinders into small spools, approximately 3cm in height. Meanwhile, crumble the bread and fry it in a pan with oil perfumed by garlic in its skin and rosemary, until it becomes golden and crisp. Place the spools upright on a baking sheet, bake in the oven at 180°C for 5 minutes, turn them, scatter the fried breadcrumbs over the top, and return to the oven at 200°C for 5 minutes until a flawless, golden gratin is realized.

For the finishing touches:
Warm the velouté with a few decorative mussels and clams, coarsely chop the samphire, and preserve it in the refrigerator, draped under paper gently moistened with sea water.

For the presentation:
Select a dark or anthracite wide-rimmed deep plate with a rich, tactile texture. Pour a veil of warm fish broth upon the base. Gracefully nestle the gratinayed green pasta spools in the center, allowing the golden linguine filling to peek through. Disperse the brilliant green samphire and the reserved mollusks all around.