Cheesy Spinach and Ricotta Stuffed Shells

Method

1. Preheat the oven to 375°F with racks in the middle and upper third. Bring a large pot of salted water to a boil. If using fresh greens, prepare an ice bath.
2. If using fresh greens, blanch them in the boiling water for 20–40 seconds until wilted. Transfer to the ice bath, then drain and squeeze out excess water. Set aside. If using frozen greens, thaw under cool water, squeeze dry, and set aside.
3. Return the water to a boil. Add the jumbo shells gently and cook until pliable but not fully al dente, about 10 minutes, stirring occasionally. Drain, return to the pot, and toss with the olive oil to prevent sticking.
4. In a food processor, drop the garlic through the feed tube while running. Stop, scrape down the sides, then add the squeezed greens. Process until finely chopped.
5. Add the ricotta and process until blended. Add half the mozzarella (reserve the rest), all the Parmesan, chives, pepper, red pepper flakes, and salt. Pulse to combine. Taste and adjust seasoning. Add the egg and process until just mixed.
6. Spread 1 cup of marinara sauce in the bottom of a large baking dish (or divide between a 9x13-inch dish and a smaller one).
7. Stuff each intact shell with about 1½ to 2 tablespoons of the filling. Arrange in the dish(es) in rows. Spoon the remaining marinara over the shells, then top with the reserved mozzarella.
8. Cover tightly with foil and bake on the middle rack for 30 minutes. Remove foil, move to the upper rack, and bake 5–10 more minutes until the mozzarella is melted and lightly golden.
9. Garnish with grated Parmesan and fresh basil. Leftovers keep refrigerated for up to 4 days or frozen for several months.