First, prepare the spinach. Put it into a large sieve or colander and pour over a kettleful of boiling water so that it wilts. Leave it to drain and once it is cool enough, squeeze out as much excess liquid as possible before chopping roughly. Set aside.
Heat some olive oil in a large frying pan and add the mushrooms. Fry them over a fairly high heat for five minutes or so until they are nicely browned and have given out all their liquid. Tip them out into a bowl and set aside.
Pour a little more olive oil into the pan and add the shallot. Fry for a few minutes until starting to soften. Add the garlic and fry for a few minutes more before adding the white wine. Allow to bubble until most of the liquid has evaporated.
Return the mushrooms to the pan along with the chopped spinach and mix everything together. Add the creme fraiche along with a generous seasoning of salt and pepper.Simmer gently so the sauce thickens a little.
Meanwhile heat your grill to its highest setting and bring a large pan of salted water to the boil and add the gnocchi. Cook according to packet instructions but generally the moment they rise to the surface, they are ready. Drain.
Grate some nutmeg into the sauce and add the parsley. Taste and adjust the seasoning if necessary. You can be quite generous with the nutmeg. Mix the gnocchi in with the sauce then spoon into a gratin dish. Grate over a generous amount of parmesan and place under the hot grill for a few minutes until golden and bubbling. Leave to cool for a minute before eating or you’ll burn your mouth (like I did).