There’s a day every autumn when I suddenly remember you can bake potatoes. It’s a wonderful day.
This isn’t a recipe for a baked potato, but it is a comforting and luxurious potato recipe for when it’s cold and dark and you might be coming down with something. I made it because I got a text saying ‘Could you please make a dinner with a lot of iron and vitamin B12’. It’s basically a potato gratin with a layer of secret spinach.
Set your oven to 180°C.
Spinach first: drop a generous quantity of spinach (I used about 500g but more would have been more than fine) into boiling water until it wilts. Drain, refresh under cold running water, and then squeeze out all the water you can until you’re left with the same perfect shining ball of spinach I mentioned in the last email. It doesn’t have to be spinach, incidentally – I’ve done this with kale, or you could use cavolo nero or chard, or an iron-y green of your choice.
Now: butter a roasting dish for your gratin. Mine is a circular one about the size of a dinner plate.
Scrub and peel 1kg of potatoes – I used waxy ones (Triplos, if you’re wondering). Now slice them as thinly as you can: if you have a mandoline, use it here. I used the slicing attachment on a food processor. The thinner the better.
Add a layer of potatoes to your roasting dish, letting the slices overlap. When you have a whole layer, give it some sea salt and a generous amount of black pepper. Add another layer: you’re basically building a drystone wall of carbohydrate here. Season each layer as you go.
When you’re about halfway through your pile of sliced potatoes, stop. Now you want to add your layer of secret spinach. Chop the ball of spinach and disperse it across the potatoes. Slice a few cloves of garlic (for me, this was about five) and strew them across the spinach too. Don’t forget to season! You could grate some nutmeg (not too much) at this point – I didn’t but I’m absolutely certain it’d work and now that I’ve thought of it I’m definitely going to have a go.
Now you can finish making your gratin. Add layers with the potato slices you have left, making sure you keep some nice-looking slices for the top layer and hide any wonky ones lower down. Don’t forget to season each layer.
When you’re done, it’s time to add cream. This amount of potatoes will drink up about 600ml of double cream (you could thin it with a little whole milk if you like; we don’t take milk in coffee so there’s never any in the house, hence we went all in on cream). Pour the cream around the edges and over the potatoes so that it flows through the gratin. Top with a little grated cheese – there’s no need to overdo it, as there’s loads of richness here already. You could add some thyme leaves here to finish it off.
Into the oven at 180°C. Check after an hour – mine took about 70 minutes in all. When it’s done, it’ll be browned and a little crunchy on top, with the cream bubbling up at the edges. If you’re worried at any point about the top burning, you can cover it with some foil. When it comes out of the oven it will be the heat of the sun: give it about ten minutes to cool down just a little, before slicing great wedges of it and diving in.
We had this as a main course, alongside a pile of watercress tossed in a dressing made with olive oil, white wine vinegar, and wholegrain mustard (we were out of Dijon, but it works!) – it cuts through the rich gratin perfectly. If you eat meat, this will become incredibly close friends with roast lamb.
I have a secret. This is the second recipe in a row that involves a shiny ball of spinach. It might be time for a whole email about things you can do with secret spinach. Fancy it?
Now read this. Rebecca May Johnson is one of my very favourite food writers. This week, she wrote this piece for her Tinyletter about a weekend in Rome, and I loved it. She also wrote the most extraordinary, moving essay about canteens and food for the people. Read them both, subscribe to her emails – you won’t regret it.