Recipe: French beef casserole

French hachis Parmentier is the kind of dish that sneaks up on you. At first glance, it’s humble — ground beef, onions, and carrots baked beneath a layer of mashed potatoes — but just like its cousin, shepherd’s pie, it’s deeply comforting, surprisingly nuanced, and exactly what you want on a frigid night. But hachis Parmentier is a little softer and more classic; it’s focused on coaxing out the best flavor from good ingredients.

Hachis Parmentier is named for Antoine-Augustin Parmentier, an 18th-century French pharmacist and agronomist who is most known for his advocacy on a topic near and dear to me: People should eat more potatoes. Apparently at the time, potatoes were not particularly popular (they were feared, actually) in France — and Parmentier was really out there doing the most to change that. He published research on potato safety, and when that didn’t work he hosted potato-themed dinner parties for local celebrities like Benjamin Franklin and staged potato publicity stunts. Hachis Parmentier was named after Antoine-Augustin in part for the potato topping, and in part due to the dish’s resourcefulness. Originally, it was meant as a way to use up leftover minced pot au feu meat.

My version, like many today, relies on ground beef simmered with carrots and onions in red wine and beef broth. I like to add a dollop of Dijon mustard; it’s not traditional, but the sharpness balances the rich beef flavor in a way that tastes right to me. I add Gruyere cheese, egg yolks, and grated nutmeg to my mashed potato topping to ensure it’s rich, with a nutty depth that adds layered flavor to every bite. The top gets extra-golden in the oven, and every bite will make you extra-happy.

Why you’ll love it

• It’s make-ahead-friendly. You can assemble the entire dish a day ahead and bake when you’re ready to wow a crowd (or just yourself)!
• An all-in-one meal. You’re getting beef, vegetables, and starch (in the form of perfectly cheesy mashed potatoes) in every bite.

Key ingredients in hachis Parmentier

• Cheesy mashed potatoes: Mash creamy boiled gold potatoes with Gruyere cheese, egg yolks, heavy cream, butter, and a little nutmeg for the perfect casserole topping.
• Ground beef: Lean ground beef is ideal so you don’t have to fuss with draining off excess grease.
• Aromatics: Garlic, carrots, and onions create a flavorful foundation for the beef filling.
• Dijon mustard: It’s not strictly traditional, but a spoonful of Dijon mustard adds a little sharp tang to cut through the rich beef filling and add balance.
• Red wine: You’ll only need 1/2 cup, so pick something you’ll enjoy drinking.

Helpful swaps

• You can swap the Gruyere cheese for Comte or less-traditional (but still delicious) aged white cheddar.
• Add chopped leeks, mushrooms, or celery to the beef filling.

Storage and make-ahead tips

• The casserole can be assembled up to one day ahead, covered, and refrigerated. Uncover before baking, and add 10 minutes to the baking time.
• Leftovers can be refrigerated in an airtight container for up to four days.

Hachis Parmentier

Serves 6 to 8

For the potato topping:

6 tablespoons unsalted butter, room temperature

2 1/2 pounds gold potatoes (about 9 medium), peeled and cut into 1-inch chunks

1 tablespoon plus 1 teaspoon kosher salt, divided, plus more as needed

1/3 cup heavy cream

2 large egg yolks

1/4 teaspoon freshly grated or ground nutmeg

3 ounces Gruyere cheese, shredded (about 1 cup)

For the beef filling and assembly:

4 tablespoons (1/2 stick) unsalted butter, divided

2 medium yellow onions, finely chopped (about 3 cups)

3 medium carrots, peeled and diced (about 1 1/4 cups)

6 cloves garlic, finely grated or minced

1 1/2 pounds lean ground beef

1 1/2 teaspoons kosher salt, plus more as needed

1/4 teaspoon freshly ground black pepper, plus more as needed

1/2 cup dry red wine

2 cups low-sodium beef or chicken broth

2 teaspoons fresh thyme leaves (4 sprigs), plus more for garnish

1 teaspoon Dijon mustard

Make the potato topping:

1. Place 2 1/2 pounds peeled and cut gold potatoes in a large saucepan or pot and add enough cold water to cover by about 1 inch. Add 1 tablespoon of the kosher salt and bring to a boil over medium-high heat. Reduce the heat to maintain a simmer and cook until the potatoes are knife-tender, 15 to 25 minutes. (This is a good time to start cooking the filling.)

2. Drain the potatoes. Pass the potatoes through a ricer into the now-empty pot, or return the potatoes to the pot and mash with a potato masher until smooth.

3. Whisk 1/3 cup heavy cream, two large egg yolks, 1/4 teaspoon freshly grated nutmeg, and the remaining 1 teaspoon kosher salt in a liquid measuring cup or small bowl until combined.

4. Add the cream mixture and 6 tablespoons room-temperature unsalted butter to the potatoes. Stir until the butter is melted and the mixture is combined. Gently fold in 3 ounces shredded Gruyere cheese. Taste and season with more kosher salt as needed. Cover to keep warm.

Make the beef filling:

1. Heat the oven to 425º F.

2. Melt 2 tablespoons of the unsalted butter in a 12-inch skillet over medium heat. Add two finely chopped medium yellow onions and three peeled and diced medium carrots. Cook, stirring occasionally, until starting to soften and brown, about 5 minutes. Stir in six finely grated garlic cloves and cook until fragrant, about 30 seconds.

3. Add 1 1/2 pounds lean ground beef, 1 1/2 teaspoons kosher salt, and 1/4 teaspoon black pepper. Cook, breaking up the beef with a wooden spoon, until browned and cooked through, 7 to 10 minutes.

4. Add 1/2 cup dry red wine and scrape any browned bits from the bottom of the skillet. Cook until the liquid is nearly evaporated, about 1 minute.

5. Stir in 2 cups low-sodium beef broth, 2 teaspoons fresh thyme leaves, and 1 teaspoon Dijon mustard. Bring to a boil. Reduce the heat to maintain a simmer and cook until the liquid is reduced by about 3/4, about 10 minutes. Taste and season with more kosher salt and black pepper as needed.

Assemble the casserole:

1. Transfer the filling to a 9-by-13-inch or other 3-quart baking dish and spread into an even layer. Dollop the potato topping over the filling with a flexible spatula, then spread the topping evenly over the filling, going all the way to the edges of the baking dish. Dice the remaining 2 tablespoons unsalted butter and scatter over the potatoes.