Fresh basil and red pepper flakes, for serving, optional
Salt + Pepper (about 1 tsp salt and 1/2 tsp pepper, more or less to taste)
Heat oil in a large cast iron skillet over medium high heat. When oil is hot, add ground beef and cook, breaking up with the back of your spoon until fully cooked through, about 5-7 minutes. Season well with salt and pepper.
Add the entire jar of marinara to the skillet, and then add 1 cup water to the empty marinara jar and give it a shake. Pour into skillet.
Break up uncooked lasagna noodles and add to skillet. Gently toss together until all noodles are nestled into the sauce. Bring to a boil, then reduce heat to medium low, cover, and simmer for 20-25 minutes, stirring occasionally, until noodles are al dente. Season to taste with salt and pepper.
When noodles are cooked, dollop ricotta cheese all over the top, followed by shredded mozzarella. Cover and cook another 3-5 minutes, until cheese is melted.