In a large pot, heat the olive oil over medium-high heat. Season the beef short ribs with salt and pepper. Add them to the pot and sear on all sides until browned. Remove and set aside.

In the same pot, add the diced onion and minced garlic. Sauté until the onion is translucent.

Return the short ribs to the pot, add the marinara sauce, and Italian seasoning. Cover and simmer on low heat for about 2 hours, or until the meat is tender and falls off the bone.

In a separate skillet, heat a little olive oil over medium heat. Add the shrimp and season with salt and pepper. Cook until the shrimp turn pink and opaque, about 3-4 minutes. Remove from heat and set aside.

Meanwhile, bring a large pot of salted water to a boil. Cook the lasagna noodles according to package instructions until al dente. Drain and lay them flat on a clean kitchen towel to prevent sticking.

Preheat your oven to 375°F (190°C). In a 9x13 inch baking dish, spread a thin layer of the marinara sauce on the bottom.

Layer 3 lasagna noodles over the sauce, followed by half of the ricotta cheese, half of the shredded mozzarella, half of the cooked short ribs (shredded), and half of the shrimp.

Repeat the layers, starting with marinara sauce, 3 noodles, the remaining ricotta, the remaining mozzarella, the remaining short ribs, and the remaining shrimp.

Top the final layer with the last 3 noodles, the remaining marinara sauce, and sprinkle with the grated Parmesan cheese.

Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes. Remove the foil and bake for an additional 15 minutes, or until the top is golden and bubbly.

Allow the lasagna to cool for about 10 minutes before slicing. Garnish with fresh basil before serving.