Featuring paccheri rigati, a ribbed, tube-shaped pasta, this over-the-top casserole cooks in a 9"-diameter springform pan. But feel free to use rigatoni and a 9x9x2" baking dish instead.

Yield: Makes 6 to 8 servings

1/4 cup (1/2 stick) unsalted butter plus more for pan
1/3 cup plus 1 1/2 cups grated Parmesan, divided (about 3 1/2 ounces total)
1/4 cup all-purpose flour
4 cups whole milk
1 cup shredded Fontina cheese
1 large egg
Kosher salt and freshly ground black pepper
1 pound paccheri rigati or rigatoni
1 cup shelled fresh or frozen peas
2 cups coarsely chopped arugula
1 cup plus 2 tablespoons coarsely chopped flat-leaf parsley
1/2 cup plus 2 tablespoons coarsely chopped fresh mint
1 cup ricotta (about 9 ounces)
1/2 teaspoon finely grated lemon zest

Butter pan. Dust pan all over with 1/3 cup Parmesan. Melt 1/4 cup butter in a large saucepan over medium heat. Add flour; whisk for 2 minutes. Gradually whisk in milk. Bring to a simmer, whisking often. Reduce heat to medium. Cook, whisking frequently, until sauce is thickened, about 20 minutes. Remove from heat. Whisk in Fontina and 1 cup Parmesan. Add egg; whisk to blend. Season with salt and pepper. Cover sauce and keep warm.

Arrange a rack in upper third of oven; preheat to 375°F. Cook pasta in a large pot of boiling salted water, stirring occasionally, until almost al dente (pasta will continue to cook while baking). Using a large slotted spoon, transfer pasta to a large bowl. Add peas to pasta water; cook until just tender, about 1 minute. Drain peas; add to bowl with pasta. Stir in cheese sauce. Add arugula, 1 cup parsley, and 1/2 cup mint to pasta mixture; mix to evenly incorporate.

Transfer half of pasta mixture to prepared pan. Mix ricotta and lemon zest in a small bowl; dot half of ricotta mixture over pasta. Spoon remaining pasta mixture into pan and dot with remaining ricotta mixture. Sprinkle with 1/4 cup Parmesan.

Bake pasta for 30 minutes. Sprinkle with remaining 1/4 cup Parmesan. Bake pasta until top is golden brown, about 10 minutes longer. Let rest for 30 minutes; remove pan sides. Sprinkle with 2 tablespoons parsley and 2 tablespoons mint and cut into wedges.