Gather ingredients: lasagna noodles (oven-ready or regular), ground beef or Italian sausage, onion, garlic, marinara sauce, crushed tomatoes (optional), ricotta cheese, mozzarella cheese, Parmesan cheese, eggs, olive oil, salt, pepper, Italian seasoning, fresh basil or parsley (optional)
Preheat oven to 375°F (190°C)
Cook noodles if using regular lasagna noodles (boil until al dente, drain, and set aside)
Sauté onion in olive oil until softened
Add garlic and cook 30–60 seconds
Brown ground beef or sausage until cooked through; drain excess fat if needed
Season meat with salt, pepper, and Italian seasoning
Stir in marinara sauce (and crushed tomatoes if using); simmer 10–20 minutes
Mix ricotta with egg, salt, pepper, and Parmesan (and chopped basil/parsley if using)
Assemble in a baking dish:
Spread a thin layer of meat sauce on the bottom
Add a layer of noodles
Spread a layer of ricotta mixture
Sprinkle mozzarella
Repeat layers until ingredients are used, finishing with sauce and mozzarella/Parmesan
Cover with foil
Bake covered 25–35 minutes (until bubbly)
Uncover and bake 10–20 minutes more (until browned and hot)
Rest 15–25 minutes before slicing and serving