Preheat oven to 400°F. In a medium bowl, stir together the ricotta, eggs, pesto, salt, and pepper. Set aside.
In a 6–7-quart Dutch oven over medium-high heat, brown the beef and sausage until no longer pink. Drain off excess grease. Transfer the meat to a large bowl. Stir the marinara sauce into the meat mixture until completely combined. Set aside.
Spread about 1-2 cups of the meat sauce in a thin layer in the bottom of the Dutch oven. Add a layer of about 3-4 lasagna noodles on top, breaking the noodles to fit.
Spread ⅓ of the ricotta mixture on top of the noodles. Layer with ⅓ of the remaining meat sauce, 1 cup of mozzarella, and 2 tablespoons of Parmesan cheese.
Repeat the layers two more times in the same order: noodles, ricotta, meat sauce, mozzarella, and Parmesan.
Cover the pot and bake for 30 minutes. Remove the lid and continue baking for 15-20 minutes, until the filling is hot and bubbly and the noodles are tender. If you’d like the top of the lasagna even more browned and crispy, place the Dutch oven under the broiler for a few minutes at the very end. Just keep a close eye on it so that it doesn’t burn.
Allow the lasagna to rest for at least 15-20 minutes (or longer) before serving. Garnish with fresh herbs, if desired.