The Food Lab Turbo: Creamy Brussels Sprouts Lasagna
There seems to be a misconception that vegetarians and vegetarian food are, by definition, healthy and light. At least, for the sake of this article, let's pretend that misconception exists.
Let's also, for the sake of the article, assume that being a decadent lard-butt is not something to look down upon, but a lifestyle choice that should be commended. At least every once in a while. I mean, even vegetarians love to stuff themselves with delicious gooey cheese, cream, and carbs every once in a while, right?
If ultimate indulgence, supreme creaminess, and a ridiculous amount of tasty goo are what you're after, this recipe—a layered lasagna with mushrooms, seared Brussels sprouts, and plenty of cheese—is a good way to get you there. The mushrooms and Brussels sprouts? Yeah, they're in there too, but they are there entirely for the sake of pleasure. I add Brussels sprouts to my rib-stickers not because they're green and healthy, but because they're damn delicious. The green and healthy part is just an added bonus.
First things first: I use no-boil lasagna noodles for pretty much all of my lasagna recipes. They're easier to assemble and I like their flat shape. The one problem? It's difficult to tell just how much liquid they're going to absorb if you use them completely raw in a dish. What looks like a nice sauce can end up dry by the time the lasagna finished baking. To solve this problem, I use a trick I learned from Cook's Illustrated: soak the noodles in water beforehand. By letting them soak for about 15 minutes in warm water, they hydrate, which prevents them from soaking up too much more liquid as they bake later on.
The Mushroom Duxelles
While the noodles soak, we need to make mushroom duxelles, which is a fancy French word that roughly translates into "mushrooms that have been chopped and cooked with cream and aromatics into a paste with the kind of flavor that would make the more Victorian of your relatives convinced that to partake in it would bring grievous moral injury to the soul."
It starts by washing button mushrooms. (Forget what you've heard about 'shrooms absorbing water when you wash them. The amount they take up is a negligible amount close to 1%.)
Next, you need to chop them. You can do it by hand (I like to crush them between my thumb and forefingers before giving them a good once over with a knife), but it's far easier to pulse them in a food processor in batches. A moderately rough chop is what you're looking for.
Start cooking those chopped mushrooms with butter in a large skillet. The goal is to get them to completely lose their moisture and start browning. They'll get wet at first, then they'll eventually dry out and start to sizzle.
Once the mushrooms have deepened in color, it's time to add aromatics: shallots, garlic, and picked thyme leaves are classic duxelles flavorings.
Next, the heavy cream. Though duxelles are often cooked with a touch of brandy or cognac, I find the flavor gets a little too sweet and intense for the finished dish. I want the mushrooms to blend and meld with the other flavors.
The cream will eventually cook down and tighten up, forming a mixture that is rich and almost paste-like. You're looking for a consistency that you can spread easily on a lasagna noodle. (And don't forget to season it!)
The Creamed Brussels Sprouts
Next up: the sprouts. You can slice them by hand, but for this recipe, where I want them to really melt into the sauce, I prefer to use the grating dish of a food processor. (If you don't have one, you can patiently grate them on a box grater. Just watch your fingers).
Finger shredding means less structure to break down and more surface area for browning, which adds that sweet, nutty flavor to the finished dish.
You want to start by searing off those grated Brussels sprout leaves in oil, letting them char deeply before scraping them off the bottom of the pan and flipping them. Repeat this a few times until a good 50% of the sprouts have been charred before adding more cream.
Once the cream reduces, it'll look like this. Pretty? No. Delicious? Sure is. And don't worry, it gets layered into the lasagna, where that drab brown color melds into the mix.
The Cheese Sauce
Our last ingredient is a basic besciamella, or white cheese sauce. I make mine the classic way: butter and flour roux-thickened milk, to which I add nutmeg and grated mozzarella cheese.
The key is to remove the sauce from heat as you add the cheese to ensure that it doesn't clump or break. Smooth, shiny, and gooey is what you're looking for here.
There's not too much rhyme or reason (not to be confused with thyme and season) when assembling a lasagna. There are three basic rules to remember:
- Make sure you start with sauce and finish with sauce, the bottom layer to prevent the noodles from sticking to the dish, and the top layer to brown and bubble, because what's the point of lasagna that's not brown and bubbly?
- Spread the fillings thinly. Lasagna is, after all, first and foremost a pasta dish. The pasta is what provides it with structure. You want the sauce to just coat the noodles, not pile up in a thick, messy layer.
- Alternate the layout of your noodles. Standard no-boil noodles fit three-to-a-layer in a 9- by 13-inch baking dish. I like to arrange them with two laid parallel to each other lengthwise on one end, and the third laid perpendicular to those two on the other end. With each subsequent layer, I'll reverse the layout so that the one perpendicular sheet stacks on top of the two parallel sheets from the layer before. This gives the whole thing more integrity as it bakes, and makes it easier to slice and serve at the end.
A standard pack of no-boil noodles contains 15 sheets, which is perfect for a 5-layer lasagna.
That comes out to one layer of sauce at the bottom, four layers of mushroom and Brussels sprout filling (with extra sauce and cheese in each of those layers), and a final layer of sauce and cheese on the top.
I like to add both cheese sauce and freshly grated cheese to mix it up texturally and give it more appealing mottled browning.
Once assembled, the lasagna can be baked immediately or refrigerated for up to a few days before finishing off in the oven.
Baking takes about 30 minutes in a 400°F oven.
For that final layer of flavor, I add finely grated Parmesan and a good sprinkle of parsley to the top of the dish right after it emerges
There now. Doesn't that look like something you'd want to dig into, and dig into hard?
If it comes out exactly as planned, the sliced lasagna should hold together as a nice tight stack, with the fillings just barely oozing out of the edges.
There's enough pasta and filling (and cream and butter and cheese) in here to feed eight people, but who are we kidding? This is the kind of dish designed for over-eating. Don't worry, you'll work off those calories next January, right?
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.