Instructions:
- Preheat oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish.
- Heat olive oil in a large skillet over medium-high heat. Add ground meat, breaking it up. Cook until browned, then drain off excess fat.
- Add diced onion to the skillet and cook until softened (about 5 minutes). Stir in minced garlic and Italian seasoning; cook for 1 minute until fragrant.
- Pour in the jarred tomato sauce and water. Season with salt and pepper. Bring to a gentle simmer, then remove from heat.
- In a separate bowl, combine the ricotta cheese, beaten egg, ½ cup Parmesan, parsley, salt, and pepper. Mix thoroughly until everything is evenly incorporated.
- Spread about 1 cup of the meat sauce thinly over the bottom of the prepared baking dish.
- Begin layering: Place 3-4 lasagna noodles over the sauce. Spread half of the ricotta mixture evenly over the noodles. Sprinkle with one-third of the mozzarella cheese. Spoon about 1.5 cups of meat sauce over the cheese layer.
- Repeat the layering sequence once more (Noodles, remaining Ricotta, 1/3 Mozzarella, 1.5 cups Sauce).
- Place the final layer of noodles on top. Spread any remaining meat sauce over the noodles, ensuring the pasta is fully covered. Sprinkle generously with the remaining mozzarella and a dusting of Parmesan cheese.
- Cover the dish tightly with foil (tenting slightly) and bake for 30 minutes.
- Remove the foil and bake for an additional 15–20 minutes, or until the cheese is deeply golden brown and bubbling.
- Crucially, let the lasagna rest on the counter for 10 minutes before slicing and serving to ensure structural integrity.