- Bring a large pot of salted water to a boil. Add the 12 lasagna noodles and cook until al dente, about 8-10 minutes. Drain the noodles and lay them flat on a sheet of parchment or a clean kitchen towel to prevent sticking. 
- Heat the olive oil in a large skillet over medium heat. Add the chopped onion and cook until translucent, about 3-4 minutes. Stir in the minced garlic and cook for an additional minute until fragrant. 
- Add the ground beef and ground turkey to the skillet. Cook, breaking up the meat with a spoon, until browned and cooked through, about 7-8 minutes. Drain any excess fat if necessary. 
- Pour in the crushed tomatoes and tomato sauce, then stir in dried basil, oregano, salt, and pepper. Simmer the sauce on low heat for 20-25 minutes, allowing the flavors to meld beautifully. 
- In a mixing bowl, combine the ricotta cheese and egg until smooth and well mixed. This mixture will add creaminess and help bind the layers together. 
- Preheat your oven to 375°F (190°C). In your deep baking dish, spread a thin layer of meat sauce on the bottom to prevent sticking. 
- Place 3 to 4 lasagna noodles over the sauce, slightly overlapping as needed. Spread one-third of the ricotta mixture over the noodles, followed by one-third of the meat sauce. Sprinkle with one cup of shredded mozzarella and a bit of grated Parmesan. 
- Repeat the layering process two more times: noodles, ricotta mixture, meat sauce, mozzarella, and Parmesan. Finish with a final layer of noodles topped generously with meat sauce and the remaining mozzarella and Parmesan cheese. 
- Cover the baking dish tightly with aluminum foil and bake for 40 minutes. Remove the foil and bake for an additional 15-20 minutes, or until the cheese is bubbly and golden brown. 
- Let the lasagna rest for about 15 minutes before slicing to allow it to set perfectly. 
- Sprinkle fresh basil leaves on top for a bright, herbaceous finish. Serve hot and enjoy the comforting layers of your homemade deep dish lasagna.