Start by preheating your oven to 375°F (190°C). While it's heating up, let’s prep the ingredients.

In a large skillet, heat the olive oil over medium heat. Sauté the chopped onion until it becomes translucent. Slice through the onion like it's a hot knife through butter. Then, add the minced garlic. Cooking garlic releases its savory essence, and you’ll savor the aroma filling your kitchen. It's incredible!

Now, add the ground beef (or your choice of meat). Break it up with a spatula as it cooks, allowing it to brown nicely. This adds a rich flavor. When the meat is no longer pink, you’ll want to drain any excess fat.

Pour in the crushed San Marzano tomatoes next. This canned treasure is renowned for its robust flavor. Season with salt and pepper to taste. If you go for the red pepper flakes, this is the moment to add them. Now let the mixture simmer. You're creating depth and complexity here. Let it bustle away for about 10-15 minutes.

While the meat sauce simmers, let’s focus on the cheese mixture. In a mixing bowl, combine ricotta cheese, the lightly beaten egg, and the Italian herb blend. Go ahead and mix until the ingredients melt together like a happy family. Toss in a pinch of salt and some freshly cracked black pepper. Stir in 1 cup of shredded mozzarella cheese. You’re preparing a creamy, dreamy filling.

In a 9x13 large baking dish, start layering. Begin with a scoop of meat sauce at the bottom. Place three no-boil lasagna sheets on top. Spread half of the ricotta mixture over the noodles. Next comes another layer of meat sauce, topped with 1 cup of mozzarella. Then repeat the layers.

Your third layer will finish with a final layer of noodles, meat sauce, and another cup of mozzarella cheese. For some extra flair, sprinkle the grated Pecorino Romano cheese over the top. It’s like the cherry on top of your lasagna sundae!

Cover the dish with foil and bake for 25 minutes. This allows the flavors to meld into something magical. After this time, remove the foil and bake for an additional 20 minutes, or until the cheese is bubbly and golden brown. Feel free to peek now and then – the anticipation makes it taste better!

Once it’s out of the oven, let the lasagna rest for a good 15 minutes. This part is crucial; cutting into it too soon can result in a messy plate. After waiting, sprinkle the chopped parsley on top for color. This simple step adds a touch of finesse.