How to Make It
Heat a 6-quart Dutch oven over medium-high. Once hot, add sausage, and break it up into small pieces with a wooden spoon. Add mushrooms and garlic; cook, stirring and scraping up browned bits from bottom of pot, until meat is browned and mushrooms release their liquid and soften, 18 to 20 minutes. Stir in crushed tomatoes, 1 cup water, tomato paste, 1/4 cup basil leaves, 2 teaspoons salt, and 1/4 teaspoon pepper. Bring to a simmer. Decrease heat to medium-low to maintain a gentle simmer. Cover, and cook, stirring occasionally, until flavors meld, about 1 hour. Stir in remaining 1/2 teaspoon pepper. Keep warm.
While sauce cooks, chop remaining 1/2 cup basil leaves. Stir together chopped basil, ricotta, 1/4 cup Parmigiano-Reggiano, and remaining 1 teaspoon salt in a medium bowl; set aside.
Cook noodles in a large pot of boiling salted water 8 minutes, stirring often with tongs to keep noodles from sticking together. Drain and rinse noodles briefly under cold water. Separate noodles a bit, and set aside.
Preheat oven to 375˚F. To assemble the lasagna, spread 2 heaping cups hot tomato sauce in the bottom of a 13- x 9-inch baking dish. Place one-third of noodles over sauce, overlapping just slightly. Spread half of ricotta mixture over noodles, and top with one-third of the mozzarella slices. Spread another 2 cups sauce over mozzarella, and sprinkle with 1/3 cup Parmigiano-Reggiano. Repeat layers a second time. Top with remaining noodles, remaining sauce, remaining mozzarella, and remaining Parmigiano-Reggiano.
Cover lasagna with a large sheet of aluminum foil that’s been lightly sprayed with cooking
spray (to prevent the cheese from sticking to it). Bake in preheated oven 30 minutes. Remove foil, and bake until cheese is lightly browned and sauce is bubbling, 25 to 30 minutes. Let stand 10 to 15 minutes. Cut lasagna into slices, and serve with additional Parmigiano-Reggiano.