roasted brussels sprout casserole with mushrooms and crispy shallots

This dish, an amazing marriage of roasted brussels sprouts, savory sauteed mushrooms, parmesan, and crispy shallots, was probably the most successful new dish we tried at our fake Thanksgiving party this year. And that’s saying something, considering how happy we were with the turkey and stuffing! It manages to be everything that a homey green bean casserole is (comforting, traditional, delicious), but elevated to a new level by fresh mushrooms, homemade shallot rings, and the roasted sprouts. I love green beans, but the sprouts have a more complex flavor and texture that works well here, and even sprout-haters tend to like them in this dish. It’s miles away from any gloop-laden thing you’ve had from a can, but still somehow very close to home.

Besides tasting great, this dish is great for entertaining and holiday cooking because it is easy to prepare in advance. I was worried about the sprouts losing their roasty crispness if I prepared the dish early, but the final effect of the casserole manages to be soft and crunchy in all the right places even if you do make things a few hours in advance. The crispy shallots on top give things a nice crunchy finish, and the brussels sprouts mix up with the mushrooms to make a nice tender interior without losing that roasty flavor. As far as entertaining-friendly vegetable sides go, I think this will become my new go-to recipe!

One year ago: Sunday Dinner: Scaled Down Thanksgiving (roasted bone-in turkey breast, mom’s celery mushroom stuffing)

Brussels Sprout Casserole with Mushrooms and Fried Shallots
Adapted from Gourmet via epicurious.com
Serves 8-12

3 lbs brussels sprouts, trimmed and halved lengthwise
1/4 cup olive or canola oil
salt and pepper
3/4 cup canola or vegetable oil, for frying shallots
5 medium shallots, sliced 1/8 inch thick and separated into rings
1/2 stick butter plus 1 T butter, divided (5 T altogether)
2 lbs mixed mushrooms, sliced (we used crimini and a handful of chanterelles, but buttons, shiitakes, and oysters would all be great as well)
1/4 cup white wine
1 T chopped fresh thyme
1/2 cup water
1/3 cup grated parmesan cheese

Roast sprouts: Preheat the oven to 425 degrees. Toss the trimmed and halved sprouts with the 1/4 cup oil, salt, and pepper, and spread evenly over 2 rimmed baking sheets (in one layer). Roast the sprouts, stirring/tossing occasionally, for 25-30 minutes, until they are nicely browned and tender. I was worried I had overcooked mine, but a nice deep browning adds great depth– as long as the don’t look or taste burnt, you’re ok! When they are cooked, remove and set aside, uncovered, until ready to use. You can leave them for up to 5 or 6 hours at room temperature if you like, but do cover them, loosely, once they’ve cooled.

Fry shallots: While the sprouts roast, heat the 3/4 cup canola oil in a medium skillet over medium heat (if you have a frying thermometer, it should read 250 degrees; if not, just let it heat up to medium and adjust heat if necessary as you fry). Working in a couple batches to avoid overcrowding, fry the shallots until they are golden brown, about 5 minutes per batch, turning and stirring occasionally. Watch closely, as they can go from not brown to burned quickly. Remove to a plate lined with paper towel with a slotted spoon, and leave them to drain and crisp up while you finish the rest. If you want to make these in advance, you can put the cooled rings in an airtight container lined with paper towels until you are ready to use them.

Saute mushrooms: When you’ve finished with the shallots, pour the oil out of the skillet, but don’t bother to wash it. Return it to medium high heat and add the 1/2 stick (4T) of butter. When the butter has melted, add the sliced mushrooms and saute, stirring occasionally, until they are softened and golden brown. Add the wine and thyme, season with salt and pepper, and stir as it bubbles until it reduces to just coat the mushrooms. Add the water and last tablespoon of butter, and stir until melted.

Assemble and bake: Transfer the mushroom mixture and the roasted brussels sprouts to a serving dish (13×9 or similar) and stir to combine. If you’re preparing the dish in advance, you can cover it loosely and set aside at room temp until ready to bake (I’d only recommend advancing to this stage a couple of hours in advance). When you’re ready to bake, preheat the oven to 350 (up to 400 would be ok, if you’re using the oven for something else as well; just keep an eye on it). Sprinkle the top of the brussels sprouts and mushrooms with the grated parmesan, then top with the fried shallots. Pop the casserole into the oven for about 10-20 minutes (times may vary depending on how much you let your sprouts and mushrooms cool), or until cheese is melted and the dish is warmed through. Serve immediately!