Clams Casino Stuffed Pasta Shells

Preheat the oven to 350 degrees F (175 degrees C). Line a baking sheet with aluminum foil.

Spread out bread cubes in a the prepared baking sheet, and bake in the oven until it they are completely dried, 20 to 30 minutes. Transfer to a mixing bowl.

Meanwhile, place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, crispy, and all the fat has rendered, about 10 minutes. Turn off heat, push crisp bacon to one side of the skillet, and drain most of the rendered fat.

Turn heat back on medium-high and add diced onions and peppers. Cook until they just start to soften, 2 to 3 minutes. Add garlic and cook until fragrant, about 1 minute. Add reserved clam juice, and cook, stirring, until half the liquid has been reduced, 3 to 5 minutes.

Transfer skillet contents into the bowl with the bread cubes.Pour in reserved clams and toss to combine. Add ricotta cheese, 1/2 cup Parmigiano-Reggiano cheese, parsley, salt, pepper, and cayenne. Mix well, cover, and refrigerate until needed.

Melt butter in a skillet over medium-high heat and whisk in flour until mixture turns into a light tan color, about 2 minutes. Add cold milk all at once, and whisk until smooth. Cook, whisking often, until sauce begins to simmer, 3 to 5 minutes. Sauce will not be very thick, but will thicken when baked with the shells.

Remove sauce from heat, and transfer 3/4 of it into a 9x12-inch baking dish. Reserve the rest for the top.

Meanwhile, bring a large pot of lightly salted water to a boil. Cook pasta shell in the boiling water, stirring occasionally, until about 75% tender, about 9 minutes (full cooking time would be 12 minutes). Drain and cover with just enough cold water to cover to prevent shells from drying out.

Preheat the oven to 400 degrees F (200 degrees C).

Stuff 20 shells with plenty of clam-bread mixture, and place on top of sauce, making 5 rows of 4 shells. Top with remaining white sauce and sprinkle with remaining grated Parmigiano-Reggiano.

Bake in the preheated oven until pasta is fully tender, sauce is bubbling around the edges, and the cheese on top is starting to brown, 30 to 40 minutes. Top with additional chopped parsley if desired, and serve immediately.