By whelma, member
Posted: February 21st, 2013
Drain and discard 1 cup of the juice from one of the cans of tomatoes. Put the tomatoes and the remaining juices in a blender or food processor and puree until smooth. Set aside.
Position a rack in the center of the oven and heat the oven to 450 degrees F. Put a large pot with 6 quarts water and 2 Tbs. kosher salt on to boil. Grease a 9x13-inch baking dish with 1 Tbs. of the olive oil.
Heat 2 Tbs. olive oil in a 6- to 8-quart Dutch oven or heavy-based pot over medium-high heat. When the oil is shimmering, about 1 minute, add sausage and 1/4 tsp. kosher salt. Cook, stirring occasionally, until almost cooked through and nicely browned, about 5 to 10 minutes. Transfer the sausage to a bowl with a slotted spoon, add another 2 Tbs. olive oil to the pan, and brown the onions in the same manner. Return the sausage to the Dutch oven.
Using a spatula or wooden spoon, push the contents of the Dutch oven to the side. If the pan is dry, add 1 Tbs. olive oil, and then the garlic, and cook until it just starts to sizzle and becomes fragrant, about 10 seconds.
Add the tomato sauce plus 1 tsp. kosher salt. Bring to a boil over medium-high heat, reduce to a gentle simmer, and cook for 10 minutes, stirring occasionally, so that the sauce thickens slightly.
Add the chile flakes, parsley, and basil and cook until they're heated through and their flavors have melded, about 5 minutes. Taste for salt and pepper.
Cook the pasta in the boiling salted water until it's just tender to the tooth, about 10 minutes. (Cook the pasta a little less than you normally might, because it will cook more in the oven later.)
Drain the pasta and add it to the sauce, along with the baby spinach.
Add half each of the Fontina, Mozzarella, and Pecorino Romano to the pasta mixture and toss well. Transfer to the baking dish and spread evenly.
Top the pasta with the remaining cheese. Bake until the cheese is golden brown, about 15 minutes. Let rest for 10 minutes before serving.