The Best Squash Lasagna

If there's one thing I learned as a restaurant cook—particularly during my days as the daytime lunch cook—it was how to find creative ways to reuse leftovers. Those end pieces of cod meat and bacon rinds? That'd become the lunch special chowder. Only got six confit duck legs left over from last night's service? No problem: I'll pick the meat off, grab some of those cognac syrup-poached prunes from the cheese cart, some hazelnuts from the pantry, and we've got ourselves a composed frisée salad on the menu.

It's not just a no-waste approach, it's a you'd better not waste that and it had better damn well taste better than reheated leftovers! approach, and it's one that I've carried with me back into civilian life, and it's how this recipe was born.

After a couple weeks of testing recipes for my pumpkin pizza, I was left with a half dozen roasted squashes and pumpkins, a whole bunch of diced pumpkin, and a good deal of gruyère, apple, and sage—all ingredients that had gone into the other recipe.

I figured those techniques worked well enough together for the pizza, why wouldn't they work well for a lasagna as well? Turns out they do. All it takes is a little adaptation.

Here's how to do it.

The Squash

I started with kabocha squash (a.k.a. Japanese pumpkin) which I find has the deepest pumpkin flavor of all the common varieties available in the supermarket.

Though the kabocha is referred to both as a squash and as a pumpkin, ask me why the pizza recipe was pumpkin pizza but this one is squash lasagna. Go ahead and ask. Okay, I'll tell you: It's because Google tells me that more people search for pumpkin pizza than squash pizza, but more people search for squash lasagna than pumpkin lasagna. Cynical, right?

I split it in half and scooped out the seeds with a spoon. You can save those seeds for roasting if you'd like. Might I suggest a few variations?

Next the squash gets coated in a little olive oil, seasoned with salt and pepper, and parked in a moderate oven to slowly roast.

As the squash slowly heats up, enzymes naturally present in its flesh will break down its starches into shorter, sweeter simple sugars which subsequently caramelize and brown, giving the squash plenty of sweet, rich flavor.

By the time it's done roasting, it should be easy to scoop out of the skin with a spoon.

For the filling, I played with a number of options, including straight-up squash (not rich and creamy enough), as well as enhancing it with things like heavy cream, crème fraîche, cheese, béchamel, and sour cream.

In the end I took a tip out of our extra-smooth pumpkin pie recipe by processing the flesh with cream cheese, an ingredient that helped the squash stay completely smooth and creamy while also adding some richness and tang.

Some butter also added richness, while an egg helps it to set and stay light as it bakes. A pinch of nutmeg and cinnamon enhances its flavor. The mixture was tasty, but it wasn't quite sweet enough, even with the slow roasting. A drizzle of maple syrup fixed it up.

As with my pizza, I found that adding squash in two different forms—as a roasted purée and sautéed cubes—added some nice texture and flavor to the dish.

And just as with the pizza, I added some of those diced apples to the mix as well. They don't taste particularly apple-y when combined with all the other elements, but they add some pleasant sweetness.

I sauté the squash and apple in butter until nicely browned then stir in some fresh sage. Squash and sage were born to be together. Who am I to keep 'em apart?

The Noodles

I'm a strong advocate of making things from scratch, but I'm also a strong advocate of doing things the easy way when the easy way is still pretty darn good. Sometimes this puts one part of my brain at odds with the other. Usually the thriftier, lazier side of the brain wins out.

If you want to roll out your own lasagna noodles or use store-bought fresh noodles and blanch them, you win much respect in my book. But if you reach for the box of no-boil, flat-rolled noodles (way better and easier than those wavy must-boil-first noodles, for the record), then you're still in pretty good shape. The real key is to soak them in cold water before using them.

If used straight out of the box, it's tough to predict precisely how much liquid they're going to absorb and your lasagna could end up dry. Soaking them helps mitigate this.

I soak my noodles for about half an hour while I prep other ingredients, then transfer them to clean kitchen towels to blot off any excess surface moisture.

The White Sauce

Just as there's no truly excellent bath out there that doesn't contain bubbles, I'm convinced that there's no truly excellent lasagna out there that doesn't contain a creamy white sauce. In fact, I'd go so far as to say that a good 25% of life's woes could be solved by coating them in creamy white sauce.

The one in this recipe is pretty basic. I start with a little garlic sautéed gently in butter before adding some flour.

I cook the flour down, whisking it the whole time to prevent burning, then I slowly whisk in some milk.

The key to good white sauce is right here: Make sure you don't pour the milk in too fast. When you first add it, the sauce should sputter and spit before thickening up into a thick sludge. You'll be tempted to pour in the milk fast to thin it out, but resist the urge! Continue in a steady stream, whisking vigorously the whole time until it's all incorporated.

Once it comes to a boil again, it should thicken up, at which point it's ready for the cheese. I use gruyère for this lasagna, though fontina or even low-moisture mozzarella would work fine.

You know how I told you that slowly incorporating the milk is the key to good white sauce?

Here's an even better trick:

Just apply some mechanical force and beat the crap out of it. A stick blender or a standing blender will smooth out any lumps, giving you a creamy, glossy sauce with the kind of lustrous shine that shampoo commercial models only dream of.

Assembly

With our fillings ready—the squash purée, the sautéed squash and apple, and the gruyère béchamel—and our noodles soaked, it's time to assemble our lasagna. This is the fun part.

I start with a layer of white sauce on the very bottom of the pan to make sure that the noodles don't stick. Then I layer on the noodles. Rather than going three in the same orientation, I lay one vertically and the other two horizontally.

Place the noodles on top...

...then a layer of about one-fifth of the purée...followed by a quarter of the sautéed mixture and a sixth of the white sauce.

When laying on the next layer of noodles, I'll swap the side that the vertical noodle is on so that they interlock and give the whole thing better structure.

This layering gets repeated three more times until all of the sautéed pumpkin is used, and you're left with just the top layer.

For that I add my noodles, top them with the remaining pumpkin purée followed by about 4 ounces of plain grated gruyère. The remaining white sauce gets drizzled over the top, then into the oven it goes. Whenever I make a cheese-topped casserole like lasagna or baked ziti, I like to start it under aluminum foil. This encourages the cheese to melt evenly over the surface before it gets a chance to dry out or brown.

I then remove the foil and let it continue baking until browned and bubbly. Doesn't that look like a big ol' pan full of fall right there?

It's important to let lasagna rest a bit before trying to cut it, if clean, neat portions are your concern. If not, then just throw the dish in the middle of the table and let your friends and family go at it like a pack of heathens. There are no judgments here.

There's always a debate in my head when I start to serve lasagna. On the one hand, it's always nice to get the first slice out of a casserole. On the other, you know that the second piece is going to be the prettiest because you've got yourself space to slide that spatula underneath.

Here's the solution: just serve your favorite child or friend at the table the first AND second slices. And of course, make sure to give 'em a corner piece because there's no debating those are the best, right? Do I hear any debating?

Building layers and layers of creamy, rich, full-flavored squash was our mission. I'd say we accomplished that quite nicely.