Why This Recipe Works

We wanted to lighten this Italian American standard by putting vegetables at the center of the dish while also maintaining the creamy texture and coziness of the traditional cheese filling. We accomplished this by using pea puree as a substitute for the ricotta—the peas mimicked the smooth texture of the dairy while contributing sweet vegetal flavor. Next, we added a full pound of thawed chopped spinach, which melded nicely with the pea puree, along with sautéed fennel and aromatics, all of which created a complex-tasting filling. A handful of chopped basil and lots of lemon zest brought bursts of freshness. For richness and to help bind the dish, we worked Taleggio into the filling, which further enhanced its flavors. Crushed red pepper and basil perked up the marinara sauce, and a little more Taleggio sprinkled over the dish made for a luscious, melty topping.

Before You Begin

If Taleggio is unavailable, substitute 8 ounces of shredded fontina. Passata is an uncooked tomato puree (Pomì brand may be labeled “strained tomatoes”); if you can’t find it, use regular tomato puree.

Instructions

for the sauce

Heat ¼ cup extra-virgin olive oil and 2 minced garlic cloves in medium saucepan over medium heat, stirring frequently, until garlic is fragrant but not browned, about 2 minutes. Stir in 1 can crushed tomatoes, 1 cup passata, and ½ teaspoon pepper flakes and simmer until slightly thickened, about 10 minutes. Stir in 3 tablespoons chopped basil, ¾ teaspoon table salt, and ¼ teaspoon sugar. Cover and set aside.

for the filling

Heat 1 tablespoon oil in 12-inch skillet over medium heat until shimmering. Add 1 large fennel bulb (stalks discarded, bulb halved, cored, and chopped fine); 1 large shallot, halved and sliced thin; 2 minced garlic cloves; and ¼ teaspoon salt, and cook, stirring frequently, until fennel is translucent and shallot is beginning to brown, 6 to 8 minutes. Add ½ cup water, cover, and cook for 5 minutes. Uncover and continue to cook, stirring frequently, until liquid has evaporated and fennel is crisp-tender and light golden brown, 3 to 5 minutes. Transfer fennel mixture to large bowl and set aside.

Process 1 pound thawed peas in food processor for 15 seconds. Scrape down sides of bowl. Add 4 ounces Taleggio, rind removed; 2 teaspoons grated lemon zest; ¼ teaspoon pepper; and remaining 2 teaspoons salt, and continue to process until cheese is incorporated and mixture is smooth, 15 to 30 seconds, scraping down bowl as needed. Add 1 pound frozen chopped spinach, thawed and squeezed dry, and pulse to incorporate, 5 to 6 pulses. Transfer pea mixture to bowl with fennel. Stir in 3 tablespoons chopped basil and set aside.

for the shells

Bring 4 quarts water to boil in large pot. Add 12 ounces jumbo pasta shells and 1 tablespoon salt and cook, stirring occasionally, until al dente. Drain pasta and rinse under cold water until cool to touch. Reserve 25 shells, discarding any that have broken.

Adjust oven rack to middle position and heat oven to 350 degrees. Spread 2 cups sauce over bottom of 13 by 9-inch broiler-safe baking dish. Using spoon, fill each shell with 2 tablespoons filling. Arrange shells open side up in 5 rows of 5 shells over sauce in dish. Pour remaining sauce evenly over shells (sauce will not cover shells completely). Sprinkle with ¼ cup grated Parmesan. Break remaining 4 ounces Taleggio, rind removed, into small pieces and dot evenly over top.

Cover dish tightly with aluminum foil and bake for 30 minutes. Remove foil and return dish to oven. Turn on broiler. Broil until sauce is bubbling and cheese is lightly browned, about 5 minutes. Transfer dish to wire rack and cool for 10 minutes. Serve. (Fully assembled shells can be refrigerated for up to 24 hours; increase bake time by 10 minutes.)