Cook pasta according to package instructions. In a sauce pan, cook the hamburger meat, until done. Add onion and garlic sauté for 4 minutes. Add pasta sauce and set aside. In a bowl blend ricotta cheese, egg and 1/4 cup Parmesan cheese. Coat a 9 x 13 baking dish with olive oil and spread 1 cup sauce mixture on the bottom. Top with 3 lasagna noodles. Spread 1/4 Ricotta cheese mixture on the noodles and layer on 1 cup of the sauce mixture. Sprinkle 1/2 cup mozzarella cheese on top. Repeat process three times starting with noodles and ending with remaining 1/4 cup Parmesan cheese. Sprinkle with oregano. Pre heat oven to 350 and bake for 45 min until hot and bubbly. Let stand 10 min before cutting.