Boil the noodles: Bring a large pot of salted water to a boil. Cook San Giorgio lasagna noodles until al dente. Drain, rinse briefly with cold water, and toss with olive oil to prevent sticking. Set aside.
Prep the aromatics: Dice 2 onions and mince 3 cloves of garlic. Toss them with olive oil, Italian seasoning, salt, and pepper.
Cook the onions and garlic: Heat a large pan over medium heat. Add the onion and garlic mixture and cook until softened and lightly browned.
Brown the meat: Add 1 part Italian sausage and 2 parts ground beef. Cook until browned but not overcooked.
Make the ricotta mixture: In a large bowl, combine ricotta cheese, 3 eggs, salt, pepper, basil, parsley, and 2 cups grated Parmesan. Mix until smooth.
Preheat the oven: Preheat oven to 375°F (190°C).
Start layering: Spread marinara sauce on the bottom of a baking dish. Add a layer of noodles, then a generous layer of ricotta mixture, followed by meat, mozzarella, and marinara sauce again.
Repeat layers: Continue layering noodles, ricotta, meat, mozzarella, and sauce until the dish is full. Finish with sauce on the top layer.
Bake covered: Cover loosely with foil and bake for 50–60 minutes (about 1 hour if thick).
Add final cheese and rest: Remove foil 10 minutes before done, sprinkle mozzarella on top, and bake until melted and lightly browned. Let rest 15–20 minutes before slicing.
