Preheat oven to 425°F.
Cook the sausage and onion in a large oven-proof skillet (such as a cast iron skillet) or in a Dutch oven over medium high heat, breaking up the sausage with a wooden spoon, until the sausage is no longer pink and onion is starting to soften, about 5-7 minutes. Add the garlic and cook for 30 seconds, stirring constantly. Season with a pinch of salt.
Add the red wine; bring to a boil. Once the liquid boils, reduce the heat and simmer until the liquid reduces by about half. Use a wooden spoon to scrape up any browned bits from the bottom of the pan.
Stir in the tomato paste, marinara sauce, and beef broth. Taste and season with salt and pepper, if necessary.
Bring to a boil, then stir in the lasagna noodles. Reduce the heat so that the sauce is simmering. Cook until the noodles are al dente, about 10-12 minutes. Stir the pan occasionally to prevent the noodles from sticking together.
While the noodles cook, stir together the ricotta, Parmesan, and pesto in a small bowl. Taste and season with salt and pepper, if desired.
Once the noodles are al dente, give everything a good stir. Drop tablespoonfuls of the ricotta mixture into the noodles. Sprinkle the mozzarella over top.
Transfer the skillet to the oven. Bake, uncovered, until the cheese melts and starts to brown on top, about 8 minutes.
Garnish with fresh herbs and grated Parmesan, if desired. Serve immediately.