Years ago, while studying in London, I noticed a critical detail in the way a lot of Brits eat that helps explain why their food often gets a bad rap from outsiders. Let's say, just as an example, that I'm at a pub eating dinner, and on my plate are some mashed potatoes, boiled peas, and roast meat with its pan drippings. If I were to attack that plate the way I'm most inclined to, I'd scoop up some peas and chew them up, and think something like, sweet but bland. Then I'd hit the mashed potatoes, and I'd remind myself that buttery French ones are better. And finally, I'd cut off a bite of the roast, dip it in its juices, and conclude, Not bad, but a little one-note.
But if I were to look at the imaginary bloke next to me, who happens to be eating the same hypothetical supper, I'd likely see something different. He picks up his fork and inverts it, tines down. With his knife, he pushes a wad of those mashed potatoes onto the fork's tines. Then he uses his knife to press some peas into the potatoes. Finally, he spears a hunk of meat on the fork's tip and runs the whole thing around the plate to pick up the juices. That's his bite, and, I guarantee you, it tastes much better than my piecemeal approach. Those peas weren't cooked for the purpose of being savored alone, nor were the potatoes, nor was the roast. They were always meant to go together.
This happens to also be the beauty of shepherd's pie, Britain's mashed-potato-topped meat and vegetable casserole. Instead of forcing you to assemble all of a dinner's elements into a single forkful, it does you the favor of delivering them pre-combined.
Still, that doesn't mean we can't trick out each individual component. My recipe starts with a top layer of incredibly rich mashed potatoes, loaded with enough butter and cream to make a French chef proud. Below, a meaty, ragù-like sauce of either ground lamb (more traditional) or ground beef (less so), or some combination of the two, that's packed with peas, carrots, and layer upon layer of flavor. I even busted out the Marmite for this one—it's optional, so don't close this article just because you don't have it. I also give my meat sauce a bit of Continental flair by hitting it with red wine and a dab of tomato paste. Sure, it tastes a little more Mediterranean and a little less British...but only in the best way.
Let's break it down.
The mashed potatoes follow a method that's probably familiar to Serious Eats readers by now. I start by peeling and dicing the potatoes—starchy russets, in this case—then rinse them under cold running water to wash off any excess starch that's been released from the cut surfaces.
Then I simmer them in generously salted water. I can't stress this enough: The water should taste strongly of salt, almost like seawater. Don't worry; most of that salt will go down the drain with the water. When the potatoes are tender, I drain them, rinse them again to remove any remaining excess starch (this reduces potential gumminess during mashing), and mash them with unsalted butter.
For a chunkier texture, a potato masher (pictured above) works well. If you want them smoother, you can use a ricer or, my personal favorite, a food mill assembled with its finest screen. I have yet to find a decent food mill made for home cooks, though, so if you go that route, I recommend going to a restaurant supply store for a heavier-duty one; you won't be disappointed.
Once they're mashed, you can cover the potatoes directly with plastic, which will prevent the surface from drying out. Right before I'm ready to assemble the shepherd's pie, I finish the potatoes, mixing them with hot cream, which will loosen them up just enough to make them easy to spread around.
The Meat and Vegetables
Once upon a time, shepherd's pies were likely just a casserole of leftovers—yesterday's mash, peas, carrots, and roast meat, reconfigured into a tasty baked concoction. Today, we don't need to be so thrifty. We can actually make a kick-ass meat sauce that stands on its own merits. For me, that means making it much like an Italian ragù.
First, though, we have to decide on our meat. Technically, there's not much to think about—it's called "shepherd's pie," and, last I checked, shepherds don't herd cows. Lamb, therefore, is the traditional choice. But beef is still often used in its place, especially by those who don't love lamb's gamier flavor. Even I, who absolutely adore lamb, found some of the ground lamb I tested to be overly funky, and ended up mixing it with beef to cut its intensity. Ultimately, you can use either, or a combination of both, depending on your preference.
To start, I sear half the meat in a large Dutch oven until it's well browned. Browning creates a deep, roasted flavor, but it also dries the meat out. Reserving the other half of the meat, and adding it only after browning the first half, ensures that a good portion of it remains tender.
Then I add diced aromatic vegetables, like onion, carrots, celery, and garlic, and cook them gently for a few minutes. With all the meat in there, the pan becomes too crowded for the vegetables to sauté properly, but that's not such a problem, since preserving a little freshness is important in a dish like this. That's particularly true for the carrots, since they play off the sweet peas in that classic combo of peas and carrots; bright, sweet peas and dull, overcooked carrots just don't quite work together here. I tested an alternate method that involved sautéing the vegetables separately and then stirring them into the pot once the meat was ready, but I found they lost too much bright, fresh flavor that way.
Next, I add a couple of tablespoons of tomato purée into the mix, frying it lightly in the oil to develop its flavor. This isn't enough tomato to make the sauce taste like a Bolognese, which it shouldn't, but it is enough to tint the meat lightly orange and add some complexity.
A splash of dry red wine puts the browning to a stop. Once again, this isn't necessarily a typical addition to shepherd's pie, but it adds richness and depth that are hard to beat. Plus, red wine is as popular in the UK as anywhere else, so it's not an out-of-the-question ingredient.
Once the wine has cooked down most of the way, I add chicken stock that I've sprinkled with unflavored gelatin. The gelatin adds body and viscosity to the liquid without altering the flavor significantly. I still add some flour for further thickening, but using gelatin means I don't have to add too much, since flour can dull the meat sauce's flavor if used too heavily.
Before letting it all simmer together until it's done, I toss in some thyme sprigs and a bay leaf to infuse the meat, and spike it with two of England's most widely used umami bombs: Worcestershire sauce and the yeast extract spread Marmite. If you don't have Marmite, the Worcestershire alone will suffice.
As soon as it's all cooked down and thick, I stir in some frozen peas. Now it's ready to be put together.
Putting the pie together is trickier than it might seem. I made the mistake of overfilling the dish in one of my early test batches, and set off multiple smoke alarms in my apartment when it spilled over. Luckily, I had had the foresight to set the baking dish on a foil-lined rimmed baking sheet, so the mess didn't land on the floor of my oven. You absolutely must do the same, since shepherd's pie is prone to boiling over in the oven, even when you haven't loaded an obscene amount into the dish.
Assembling it is simple. Start by spooning the meat sauce into the bottom of a baking dish; try not to go much above the halfway point in order to keep spillovers less...dramatic.
Then spoon the warm, spreadable mashed potatoes all over the top, creating a dappled surface with a spatula. That'll help create a diversity of textures, since the little peaks will crisp up more than the valleys while in the oven.
I also like to grate some Parmesan cheese on top, for both additional flavor and enhanced browning.
After baking, it's a good idea to let the pie rest for 20 minutes before serving, which will allow the meat sauce to cool down and thicken up just slightly. Using a sturdy spatula, scoop portions out onto plates. Don't worry too much about how messy those servings are. After all, it's all going to end up in the same place, and ideally it will all arrive together.