Preheat oven to 375 F.
Cook the dry lasagna noodles according to package instructions until al dente. Drain and lay flat on a kitchen towel.
In a large skillet, add two tablespoons of olive oil and sauté chopped onions until translucent, then add minced garlic and cook for an additional minute. Add ground beef and cook until browned.
Drain excess grease, then stir in tomato sauce, tomato paste, and salt. Simmer for about ten minutes.
In a separate bowl, combine ricotta cheese, beaten egg, and parsley. Mix until well blended.
In a greased baking dish, layer meat sauce, noodles, ricotta mixture, and mozzarella. Repeat layering two more times, finishing with noodles topped with meat sauce, mozzarella, and Parmesan. Cover with foil and bake for 50 minutes, then remove foil for the last 15 minutes.