Heat the olive oil in a Dutch oven or large pot and cook ground sausage, ground beef, and garlic over medium heat until well browned. Stir in onion, mushrooms, crushed tomatoes, fire-roasted tomatoes, tomato paste, and water. Season with basil, fennel seeds, Italian seasoning, salt, pepper, and parsley. Simmer, covered, for about 45 minutes, stirring occasionally.In a mixing bowl, combine ricotta cheese with egg, parsley, and ½ teaspoon salt. Set aside.Preheat oven to 375 degrees F (190 C).To assemble, spread 3 cups of the lasagna sauce in the bottom of a 9x13 inch baking dish. Arrange 5 noodles on top of sauce (I arranged 4 lengthwise and then broke one in half and arranged it vertically on the open end). Spread with one half of the ricotta cheese mixture. Top with half of mozzarella cheese slices. Spread 2 cups meat sauce evenly over mozzarella, and sprinkle with ½ cup parmigiano. Repeat layers (noodles, ricotta, mozzarella, sauce) and top with remaining parmigiano.Cover with foil: to prevent sticking, slightly crease the foil to create a tent over the lasagna.Bake in preheated oven for 25 minutes. Remove foil, and bake an additional 25 minutes (to get the crispy lasagna corners and cheese!). Cool for 10 minutes before serving.