Place a very large pan of salted water on a high heat and bring it to the boil.
TURN THE OVEN ON TO 190˚C/170˚C fan/Gas 5
Peel and bash the garlic. Remove the thyme leaves from the sprigs, wash and roughly chop.
Warm the olive oil in a medium pan. Add the garlic clove and cook for 2-3 minutes until golden.
Add the ground pork and thyme leaves and let it cook, stirring frequently, for about 10 minutes or until the meat has browned.
Add a generous grate of nutmeg to the meat and pour in the wine. Let it bubble for a couple of minutes, then add the tomatoes. Stir well and season with a pinch of salt.
Turn the heat down and simmer for about 15 minutes or until the sauce is smooth and velvety.
Meanwhile, put the frozen spinach in a pan with a little water. Cover the pan with a lid and cook over a low heat for 8-10 minutes. Check regularly to prevent burning. If the liquid dries up, add some warm water.
If you are making your own béchamel sauce , do it while the meat sauce and spinach are cooking,
Remove the garlic from the meat sauce. Stir in the spinach, along with its cooking liquid. Taste and adjust the seasoning.
Put the tagliatelle into the boiling water and cook for 2-3 minutes.
Pour two ladles of the spinach and meat sauce and a ladle of béchamel sauce into a very large oven dish. Stir to mix.
Drain the pasta, but not too thoroughly, and return to the cooking pan. Dress with a couple of ladles of the meat and spinach sauce and 1 tablespoon of parmesan.
Tip the dressed pasta into the oven dish, fluff it up with a fork and cover with the remaining meat sauce. Finish with the remaining béchamel sauce and more grated parmesan.
Place in the oven for 15 minutes until it the parmesan has melted Serve immediately.