Heat olive oil in a large pot over medium heat and sauté onion and garlic until translucent.
Add ground beef and pork, cooking until browned; drain excess fat.
Stir in tomato paste, crushed tomatoes, oregano, salt, and pepper. Simmer for 45 minutes on low heat.
In a medium bowl, combine ricotta cheese, egg, parsley, and 1/4 cup of Parmesan cheese.
Preheat oven to 375°F (190°C).
Cook lasagna noodles in boiling salted water until al dente, then drain.
Spread 1 cup of meat sauce in the bottom of a 9x13 inch baking dish.
Layer noodles, 1/3 of the ricotta mixture, and 1 cup of mozzarella cheese.
Repeat layers twice more, finishing with the remaining meat sauce, mozzarella, and Parmesan.
Cover with foil and bake for 25 minutes.
Remove foil and bake for an additional 20 minutes until cheese is golden and bubbling.
Let the lasagna rest for 15 minutes before serving to ensure clean slices.