Start the Ragu: In a large frying pan, heat 1 tablespoon of olive oil over medium-high heat. Once shimmering, add the finely diced onion and cook for about 5 minutes, stirring often, until softened.
Toss in the minced garlic and cook for another minute until fragrant. Then add the diced carrot and mushrooms. My family is not big on mushrooms, so I dice them small – sneaky but effective! Cook for 2–3 minutes.
Brown the Beef: Add the ground beef to the pan. Use a spoon to break up any large chunks and brown it thoroughly – this takes around 5–6 minutes. Do not use low-fat beef; you want that 12–20% fat for flavor and richness.
Build the Sauce: Stir in the tomato puree, oregano, thyme, Worcestershire sauce, and crumbled stock cube. Add canned tomatoes, brown sugar, salt, and pepper in the canned tomatoes. Give everything a good stir.
Bring to a boil, then lower the heat and let it simmer gently for 15–20 minutes, stirring occasionally. This is where the magic happens as all those flavors deepen and meld.
Make the Béchamel: In a medium saucepan, melt the butter over medium heat. Once it starts to bubble, whisk in the flour. Cook for 1 minute to eliminate the raw flour taste.
Gradually add the milk, whisking constantly. It might look lumpy at first – do not panic! Just keep whisking and it will smooth out beautifully. Once the sauce thickens, stir in the cheddar, mozzarella, salt, pepper, and a pinch of nutmeg if you like. Turn off the heat.
Assemble the Lasagna: Preheat the oven to 200°C (400°F). In a large baking dish, spread a thin layer of meat sauce to stop the pasta from sticking.
Add 4 sheets of lasagna pasta. You might need to break them to fit your pan – just do not overlap too much.
Spread over a third of the white sauce, followed by a third of the meat sauce. Repeat this layering process twice as much: pasta, white sauce, meat sauce.
Top with the remaining cheese – mozzarella and cheddar – for that golden crust.
Bake and Finish: Bake uncovered for 25–30 minutes until the cheese is bubbling and golden brown. You will know it is ready when the edges are just starting to crisp, and the aroma fills your kitchen.
Let it sit for 5–10 minutes before slicing. Sprinkle with chopped parsley just before serving.