In a large skillet over medium heat, cook the ground beef, onion, and garlic. Season with salt, black pepper, oregano, and basil. Sauté for 7-10 minutes until browned.
Stir in the marinara sauce and let it simmer for 5 minutes. Set aside to cool slightly.
Boil salted water in a large pot and cook the lasagna noodles until al dente, about 8-10 minutes. Drain and lay flat to prevent sticking.
In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for 2 minutes. Gradually add the milk, whisking until thickened (5-7 minutes). Season with salt and black pepper.
In a 9x13 inch baking dish, layer the beef mixture, 3 noodles, ricotta cheese, béchamel sauce, and mozzarella cheese. Repeat layers until finished, topping with mozzarella and Parmesan.
Cover with aluminum foil and bake for 25 minutes. Remove the foil and bake for an additional 15-20 minutes until golden and bubbly.
Let the lasagna rest for 10 minutes before slicing. Serve warm.
Notes
Let the lasagna rest before slicing for better presentation.