Classic Lasagna

Meanwhile, in a large pot over medium-high heat, heat oil. Cook ground beef until no longer pink, breaking up with a wooden spoon. Remove from heat and drain fat. Return beef to skillet and add garlic and oregano and cook, stirring, for 1 minute. Season with salt and pepper, then add marinara and stir until warmed through.  Combine ricotta, 1/4 cup Parmesan, parsley, and egg in a large mixing bowl and season with salt and pepper. Set aside. Cover with foil and bake for 15 minutes, then increase temperature to 400º and bake uncovered for 18 to 20 minutes.