Souped out already? Try this sweet potato gratin instead

This isn’t everyday food – it’s extravagance

Serve simply, with a quick and crunchy green salad and a lemony dressing (Rey Lopez/The Washington Post)

After a glorious, too-brief autumn, it feels like winter. The trees, bare arms outstretched towards the sky, are mostly free of leaves. Fat, furry squirrels leap from branch to branch, chasing one another’s tails in a mad quest for the last few acorns. The sun rises later than I’d like, and sets before I’m done writing for the day. Before long, it will be the end of this year.

I’m slowly getting into holiday mode and looking for excuses to indulge. Sometimes that looks like a caramel-filled bonbon after lunch. Sometimes it might be a crisp gin martini with extra olives. Sometimes it’s a slice of pie in the afternoon. Other days it might be a rich dinner with this sweet potato gratin with mushrooms and thyme at its centre.

I started dreaming up this recipe back when the days were still hot and humid. That’s how it is with recipe development – we’re always working a season or two ahead. But I could imagine how chilly the air would get come November, and what I’d want to eat after a damp day of cold, hard rain. Soup is the easy answer, but when you are looking for something a little luxurious, consider this one-pan gratin with tender vegetables bathed in salty, thyme-scented cream, dotted with mushrooms.

I like it served simply, with a quick and crunchy green salad with a lemony dressing on the side to brighten up the plate.

This isn’t everyday food – it’s extravagance. Simple, and not too expensive, the gratin works as a main course or side dish.

Sweet potato and mushroom gratin

The gratin works both as a main course or a side dish (Rey Lopez/The Washington Post)

Active time: 20 minutes | Total time: 50 minutes

Serves: 4

Creamy and rich, this sweet potato gratin makes a hearty side – but can also act as a main course, served with a green salad dressed in a pungent vinaigrette on the side.

If you can’t have onion, skip it.

No sweet potatoes? This would work with thinly sliced squash or other types of potatoes.

Out of parmesan? Use another hard, meltable cheese such as gruyere or cheddar.

Storage notes: Refrigerate for up to 4 days or freeze, wrapped airtight, for 1 month.

Ingredients:

2 tablespoons unsalted butter

¼ small yellow onion (30g), sliced (optional)

170g small mushrooms (any kind), sliced

¼ teaspoon fine salt, plus more as needed

420g double cream, divided

85g grated parmesan cheese, divided

2 large sweet potatoes (680g total), peeled and thinly sliced

1 sprig fresh thyme, plus a few fresh thyme leaves for garnish (optional)

Method:

Position a rack in the middle of the oven and preheat to 200C.

In a large frying pan over medium-high heat, melt the butter. When it begins to sizzle, add the onion, if using, mushrooms and salt. Cook, stirring occasionally, until the mushrooms release their liquid and begin to brown, about 5 minutes. Add about 120g of the double cream, using it to help you scrape up any browned bits from the bottom of the pan. Add the remaining cream and quickly stir in about half of the cheese. Nestle the sweet potatoes in with the mushrooms, fitting them into a flat layer, and add the sprig of thyme, if using. Bring to a boil. Remove from the heat, cover the skillet tightly with aluminum foil and transfer to the oven.

Roast for 25 minutes, then remove the foil and top with the remaining cheese. Continue roasting, uncovered, for another 10 to 15 minutes, or just until the potatoes are tender. Garnish with thyme leaves, if using, and serve hot, family-style.

Nutrition information per serving | Calories: 660; total fat: 51g; saturated fat: 31g; cholesterol: 177mg; sodium: 609mg; carbohydrates: 40g; dietary fibre: 6g; sugar: 9g; protein: 14g.

This analysis is an estimate based on available ingredients and this preparation. It should not substitute for a dietitian’s or nutritionist’s advice.

© The Washington Post