In a skillet, heat a tablespoon of olive oil over medium heat. Sauté the grated onion and carrot for about 5 minutes until softened. Add in the crushed garlic and minced beef, cooking until browned. Sprinkle in the dried oregano, followed by the tomato purée and Worcestershire sauce. Stir in the bay leaf and chopped tomatoes, then pour in the milk. Season with salt and pepper, and let it simmer for 15-20 minutes until thickened.

In a saucepan, melt 25g of butter over low heat, then whisk in 25g of flour, stirring continuously for about 2 minutes to create a roux. Gradually add 300ml of milk while whisking until the mixture turns smooth and begins to slightly thicken. Incorporate a pinch of ground nutmeg and the grated cheddar cheese, stirring until melted and well combined.

In a baking dish, spread a thin layer of the meat sauce on the bottom. Place two no-cook lasagna sheets over the sauce, then layer on some béchamel sauce followed by more meat sauce. Repeat the layers with the remaining sheets and sauces until finishing with a final layer of béchamel. Top with extra grated Parmesan cheese.

Preheat your oven to 190°C (375°F) and bake the assembled lasagna for approximately 50 minutes until the top is golden and bubbling.

Let the lasagna rest for about 10 minutes after baking to allow the layers to set before slicing and serving.