In a large skillet, over medium heat, cook the onion and garlic in the olive oil, until the onion is softened.
Add the strained tomatoes, tomato paste, chicken stock, sugar, oregano, salt, and red pepper flakes. Simmer, uncovered for thirty minutes. Reserve one cup of sauce for another use.
Preheat the oven to 350 degrees.
Cook the noodles according to the package directions for al dente noodles.
In a large bowl, mix together the ricotta, basil and egg.
In a deep 13x9 baking dish, place a layer of noodles. Top with a quarter of the sauce, and then a quarter of the ricotta, and a quarter of the mozzarella. Repeat this three times. Add a layer of Parmesan cheese.
Bake uncovered for thirty minutes. Sprinkle with basil leaves and serve.