By Melissa Clark
Quick-cooking farro, with its nutty flavor and plump, chewy texture, is the darling of the grain bowl, the star of countless salads and the foundation of many traditional Italian soups.
It’s also pretty wonderful mixed with mushrooms and cheese, and baked into a golden-topped gratin.
Other than homey rice bakes, there aren’t a lot of grain gratin recipes, possibly because grains are already filling enough, needing no extra heft from the addition of dairy and eggs.
But in the depths of winter, when rib-sticking dishes are at their most appealing, a farro and mushroom gratin can be exactly right. And this one works on its own, served as a meatless main course (maybe rounded out with a crisp green salad), or as a rich side dish alongside chicken or fish.
The most efficient way to make this recipe is to work through the steps concurrently. While the farro simmers away in one pot, you can brown the mushrooms in a skillet. Just be sure to get them deeply bronzed so they condense and caramelize.
After that, the shallots need only a brief stint in that same skillet, just enough so they’re tender and sweet.
I added mascarpone to give this gratin an especially creamy core, but feel free to substitute crème fraîche. The mascarpone is plusher and denser, but the pronounced tanginess of crème fraîche can be a nice contrast to the earthiness of the farro and mushrooms.
One thing to keep in mind is that farro can differ wildly among brands. Most of what you’ll find in the United States is pearled, or semi-pearled, meaning that some or all of the bran has been removed so it’s quicker to cook. But you can also use whole-grain farro. It will take longer to soften (about an hour or so), but it’s a lot more nutritious, and chewier, too, in a good way. Wheat berries and barley will also make fine substitutes. And if you’re looking for something gluten-free, try wild rice or brown rice. Gratins like this one are easy to adapt.
On that note, you can also change up the vegetables. Leftover roasted cauliflower, winter squash or Brussels sprouts will all work nicely, as will garlicky sautéed kale, and they make this warming dinner even easier to prepare — though no less satisfying to eat.
Farro and mushroom gratin
Total time: 45 minutes
In this elegant gratin, nutty farro and earthy mushrooms are baked with herbs and mascarpone into a creamy casserole topped with Gruyère. It’s a rich, meatless meal that needs nothing more than a crisp green salad to round it out, though it’s also a satisfying side dish alongside roast chicken or fish. You can prepare the entire gratin earlier in the day (leave it at room temperature), then bake it just before serving — simply add a little extra time to ensure that it emerges from the oven steaming hot through and through. Note that if you’re using tangy crème fraîche instead of mascarpone, you may not need the lemon. Taste before squeezing.
Salt and black pepper
1 1/2 cups pearled or semi-pearled farro
6 tablespoons extra-virgin olive oil, plus more as needed
1 pound mixed mushrooms (such as oyster, maitake, portobello, shiitake or cremini), cut into 1 1/2-inch pieces
6 to 8 fresh thyme sprigs
1 cup thinly sliced shallots, leeks or onion
1 cup mascarpone or crème fraîche
1 cup chopped parsley leaves and tender stems, chives, mint or cilantro
8 ounces shredded Gruyère (about 1 2/3 cups)
Lemon wedges, for serving (optional)
1. Heat oven to 425 degrees. Bring a medium pot of well-salted water to a boil over high heat.
2. Add farro to the pot, and cook according to package directions until tender (which should be about 20 to 30 minutes). Drain well in a colander. While still warm (and leaving the farro in the colander, if you like), drizzle the grains with enough olive oil to coat lightly, tossing well to prevent from sticking. Set aside.
3. While farro is cooking, prepare the mushrooms: In a large ovenproof skillet, heat 3 tablespoons of the oil over medium-high until hot but not smoking. Add enough of the mushrooms to cover the skillet in one layer without crowding and half the thyme. Cook, undisturbed, until bottoms of the mushrooms are golden brown, 3 to 5 minutes. Stir and let brown on the other side, 2 to 3 minutes more. Use a slotted spoon to transfer mushrooms and thyme to a plate, and season with salt and pepper. Add another 2 tablespoons oil to the pan and repeat with another layer of mushrooms and thyme, adding them to the plate when done. Repeat with more mushrooms if necessary.
4. Add remaining 1 tablespoon oil to skillet and stir in shallots and a large pinch of salt and pepper. Sauté until tender and golden brown, 4 to 6 minutes.
5. Remove skillet from heat and return mushrooms to the pan (discarding the thyme sprigs). Stir in farro, mascarpone and 3/4 cup parsley. Taste and add more salt and pepper, if needed. Spread mixture evenly in the skillet and sprinkle Gruyère on top. Bake until the farro is hot and Gruyère is melted, 10 to 15 minutes. Turn on broiler and broil for 1 to 2 minutes until Gruyère starts to bubble and develop brown spots.
6. Sprinkle with remaining parsley and serve with lemon wedges for squeezing on top, if you’d like.