Gnocchi Alla Sorrentina (Baked Gnocchi With Tomato and Mozzarella) Recipe

1. For the Gnocchi: Adjust oven rack to middle position, and preheat oven to 450°F (232°C). Set potatoes either on a wire rack set over a baking sheet, on a baking sheet lined with a layer of salt, or directly on the oven's racks. Bake until completely tender throughout when pierced with a fork, about 45 minutes. Transfer potatoes to a work surface; if making the dish start-to-finish, leave oven on. Using tongs to hold hot potatoes, slice each in half lengthwise.

2. Using a spoon, scoop potato flesh into a ricer or food mill fitted with the finest disk. Press potato flesh onto a clean work surface, spreading it into an even layer, and allow steam to escape for a few minutes.

3. Drizzle egg yolks all over. Sprinkle with 1 1/2 teaspoons salt.

4. Scoop 3/4 cup (100g) flour into a fine-mesh sieve and tap to dust flour all over potatoes.

5. Using a pastry blender or bench scraper, chop down repeatedly all over to cut flour and egg into potato.

6. Using a bench scraper, gather up shaggy potato mass and pat into a loose ball. Press ball flat with hands, then fold in half using bench scraper and press down again.

7. Scoop remaining 1/4 cup (30g) flour into sieve and dust all over potato dough. Continue to gently fold and press, just until a uniform dough comes together; make sure to simply fold and press down and avoid the smearing motion more commonly used when kneading bread. Add additional flour as necessary to achieve a dough that's tender and moist yet can hold its shape, but not wet and sticky (whether you need more flour, and how much you might need, will depend on natural moisture content of the potatoes you use, which is highly variable, but a dough that's too wet and pasty is prone to falling apart when boiled and baked later).

8. Dust potato dough all over with flour and gently form into a log.

9. Clean work area well and dust with fresh flour. Using bench scraper, slice off a roughly 2-inch-thick portion of dough and roll into a snake about 1/2 inch thick; use a light touch as you roll, trying to use your palms more than your fingers, and dusting as necessary with flour to prevent sticking.

10. Using bench scraper, cut snake into 1-inch portions, trimming off uneven ends as necessary. If desired, gently roll each gnocco on the tines of a fork to give it a ridged exterior. Transfer gnocchi to a well-floured area or baking sheet and repeat with remaining dough. If not cooking recipe start-to-finish, baking sheet of gnocchi can be transferred to the freezer at this point (see make-ahead and storage section for full freezing instructions).

11. Meanwhile, for the Tomato Sauce: While potatoes are baking, in a 3-quart saucepan or saucier, heat oil with garlic over medium heat, and cook until garlic is golden all over, 3 to 5 minutes. Add passata and basil; if passata is very thick like ketchup, stir in 1/2 cup (120ml) water. Bring to a gentle simmer, then lower heat to mantain bare simmer and cook for 10 minutes. Season lightly with salt and discard garlic and basil. Set aside.

12. To Assemble and Bake: If oven isn't already on, adjust oven rack to middle position and preheat oven to 450°F (230°C). Bring a large pot of salted water to a simmer. Transfer 1 1/2 cups (355ml) tomato sauce to a large mixing bowl. Working in batches to prevent crowding the pot, add gnocchi to simmering water and cook, gently shaking the pot as needed to keep them from sticking, until they float to the surface. Using a spider skimmer, lift floating gnocchi from the water and let drain, then transfer to bowl with tomato sauce. Toss very gently with a large spoon to coat, being careful not to break gnocchi.

13. In a 3 3/4- or 4-quart baking dish, spoon 1/4 cup (60ml) tomato sauce and spread in an even layer. Fill baking dish just shy of halfway with sauce-covered gnocchi. Scatter half the mozzarella on top, then cover all over with an even sprinkling of grated Parmigiano-Reggiano.

14. Spoon more gnocchi and sauce on top to nearly fill dish (there's a chance you'll have a little extra gnocchi that won't fit; that's okay, save them for a snack). Top with the remaining mozzarella, then coat with an even sprinkling of grated Parmigiano-Reggiano.

15. Set baking dish on a rimmed baking sheet and bake until bubbling all over and mozzarella is melted, 10 to 15 minutes. If desired, turn on broiler and continue to cook until cheese has crisped and browned lightly on top, 1 to 2 minutes longer.

16. Transfer baking dish to a heatproof surface and let rest 5 minutes. Divide gnocchi between individual serving bowls, top with fresh basil leaves, and serve.

Special Equipment

Potato ricer or food mill; bench scraper; 3.75- or 4-quart baking dish, such as a 9- by -13-inch baking dish

Notes

We strongly recommend making your own gnocchi, since almost all store-bought products have bad texture and flavor. However, if you have a source for good store-bought gnocchi, you will need about 2 pounds (900g).

A good jar of passata makes this sauce incredibly easy, but you can also use one 28-ounce can of whole peeled tomatoes (don't worry about the extra 3.5 ounces, it'll all shake out in the wash). If you do use whole peeled tomatoes, try to find ones that are packed in purée and not their juices (this will help make a properly thickened sauce more quickly), and blend them first to a smooth purée using a blender or immersion blender.

Make-Ahead and Storage

The formed, uncooked gnocchi can be frozen on the sheet tray. Once frozen, use a thin metal spatula to free from sheet tray, transfer to a zipper-lock bag, press out excess air, and seal. Return to freezer until ready to use. To cook, add frozen gnocchi directly to gently simmering water. The assembled casserole can be wrapped in plastic and refrigerated for up to 6 hours; to bake, remove plastic, add casserole to cold oven, set oven to 450°F (230°C), and cook until bubbling all over and heated throughout; finish with optional broiling step as directed.