In a large pan or skillet, heat a few tablespoons of olive oil over medium heat.
When pan is heated, brown and chop sausage thoroughly. Remove from pan and set aside, leaving about tablespoon of drippings left.
Add chopped onion into the pan and sauté about 5 minutes, or until translucent. Then add garlic, Italian seasoning and crushed red pepper flakes. Sauté another minute or so until the garlic is fragrant.
Add sausage back into the pan, along with the jar of sauce and broken, dry lasagna pieces.
Cover the mixture with chicken stock. Bring to a simmer, making sure that the pasta pieces are mostly submerged. Reduce heat slightly, and continue to simmer uncovered for about 25 minutes, until the pasta is al dente and the mixture has reduced. Be sure to stir occasionally to prevent sticking. Add another splash of water or chicken stock if needed.
While the pasta is simmering, make the ricotta mixture. In a small mixing bowl, combine ricotta, 1/4 cup grated parmesan, 1/4 cup grated mozzarella, and chopped parsley. Season with salt and pepper to taste.
When pasta is cooked and al dente, remove the pan from heat. Pour in heavy cream and remaining grated parmesan. Dot large spoonfuls of ricotta mixture on top of lasagna. Sprinkle top with remaining 1/4 cup of grated mozzarella and cover with lid for a few minutes to melt.
Serve topped with fresh basil and additional grated parmesan, if desired.