Season with salt, pepper, and nutmeg. Remove from heat.
Assemble the Casserole:
In a deep baking dish, add a layer of cooked spaghetti.
Spread the meat sauce evenly over the spaghetti.
Add another layer of spaghetti.
Pour the béchamel sauce on top, spreading it evenly.
Add Cheese:
Sprinkle grated mozzarella and cheddar (or parmesan) on top.
Bake:
Preheat oven to 200°C (400°F).
Bake for 20-25 minutes or until the top is golden brown and bubbly.
Serve:
Let the casserole rest for 5-10 minutes before cutting and serving.
Enjoy!