1-First Step: Start by preheating your oven to 375°F and gathering all ingredients. This sets the stage for smooth cooking and ensures you have everything on hand, like boiling a pot of salted water for the lasagna noodles.

2-Second Step: Cook 12 lasagna noodles in the boiling water until they are al dente, which takes about 8-10 minutes. Once done, drain and rinse them with cold water to stop the cooking process, then lay them flat on a clean surface to cool; this prevents sticking and makes rolling easier.

3-Third Step: Prepare the meat sauce by browning 16 ounces of ground beef over medium-high heat in a skillet. Add 1/2 cup diced onion and cook until soft, about 3-4 minutes, then mix in 3 minced garlic cloves along with 1 teaspoon salt, 1/2 teaspoon black pepper, and 1/2 teaspoon oregano; sauté for another minute to release flavors.

4-Fourth Step: Stir 32 ounces of marinara sauce into the meat mixture and let it simmer for 5-10 minutes. This builds a rich base; while it simmers, mix 15 ounces ricotta cheese, 1 large egg, 1/4 cup shredded Parmesan cheese, 1 1/2 cups shredded mozzarella cheese, and 1/4 cup chopped parsley in a bowl to create the cheese filling.

5-Fifth Step: Spread about 1/2 cup of the meat sauce evenly across the bottom of a baking dish. On each cooled noodle, spread roughly 1/4 cup of the cheese mixture and top with a heaping tablespoon of meat sauce, then carefully roll them up and place them seam-side down in the dish.

6-Sixth Step: Cover the rolled noodles with the remaining meat sauce and sprinkle the rest of the 1 1/2 cups shredded mozzarella cheese on top. Cover the dish with foil and bake in the preheated oven for 40 minutes; this allows the flavors to meld and the cheese to melt perfectly.

7-Seventh Step: After baking, remove the foil and broil on high for 2-3 minutes until the cheese turns light golden. Let it rest for a few minutes before garnishing with extra chopped parsley; this final touch adds freshness and makes the dish ready to serve hot.