Quick Recipe Version (TL;DR)

Yield: 6 servings
Prep Time: 25 minutes
Cook Time: 55 minutes
Total Time: 1 hour 20 minutes

Quick Ingredients

2 lb (900 g) floury potatoes, peeled and chunked
4 tbsp unsalted butter + 2 tbsp for topping (optional)
1/2 cup (120 ml) whole milk
1/4 cup (60 ml) sour cream (optional)
1 large egg yolk
1.5 lb (680 g) ground lamb
2 tbsp olive oil
1 large onion, finely diced
2 carrots + 2 celery stalks, finely diced
3 cloves garlic, minced
2 tbsp tomato paste
1 tbsp Worcestershire sauce
1 tsp fresh thyme + 1 tsp fresh rosemary (or 1 tsp dried mixed)
2 tbsp all-purpose flour
1 cup (240 ml) beef or lamb broth
1/2 cup (120 ml) dry red wine (or extra broth)
1 cup frozen peas (and 1/2 cup frozen corn, optional)
Salt and freshly ground black pepper
2 tbsp grated Parmesan and chopped fresh parsley for topping (optional)

Do This

1. Preheat oven to 400°F (200°C). Grease a 2-quart baking dish.
2. Boil potatoes in salted water until very tender, 15–18 minutes. Drain well.
3. Mash potatoes with butter, milk, sour cream, egg yolk, salt, and pepper until smooth and fluffy.
4. Brown lamb in olive oil, then add onion, carrots, celery, and garlic. Cook until softened.
5. Stir in tomato paste, Worcestershire, herbs, salt, and pepper. Sprinkle with flour, then add broth and wine. Simmer until thickened; stir in peas (and corn).
6. Spread lamb ragout in baking dish. Spoon or pipe mashed potatoes on top; rough up the surface. Sprinkle Parmesan if using.
7. Bake 25–30 minutes until bubbly and golden. Rest 10–15 minutes, garnish with parsley, and serve.

Why You’ll Love This Recipe

Classic, cozy comfort food with rich lamb, tender vegetables, and a velvety, buttery potato topping.
Make-ahead friendly: assemble in advance and bake when you are ready to eat.
Flexible: swap in different vegetables or use beef for a classic cottage pie variation.
Perfect for feeding a family or a small gathering, and the leftovers reheat beautifully.

Grocery List

Produce: Potatoes, onion, carrots, celery, garlic, fresh thyme, fresh rosemary, fresh parsley (optional), bay leaf (optional).
Dairy: Unsalted butter, whole milk, sour cream (optional), egg, grated Parmesan (optional).
Pantry: Ground lamb, olive oil, tomato paste, Worcestershire sauce, beef or lamb broth, dry red wine (or extra broth), all-purpose flour, frozen peas, frozen corn (optional), salt, black pepper.

Full Ingredients

For the Buttery Mashed Potato Topping

2 lb (900 g) floury potatoes (such as Yukon Gold or Russet), peeled and cut into 1 1/2-inch chunks
4 tbsp (60 g) unsalted butter, plus extra for dotting on top if desired
1/2 cup (120 ml) whole milk, warmed
1/4 cup (60 ml) sour cream (optional, for extra creaminess and tang)
1 large egg yolk
1 tsp kosher salt (or to taste)
1/4 tsp freshly ground black pepper (or to taste)

For the Lamb and Vegetable Ragout

2 tbsp olive oil
1.5 lb (680 g) ground lamb
1 large yellow onion, finely diced
2 medium carrots, finely diced
2 celery stalks, finely diced
3 cloves garlic, minced
2 tbsp tomato paste
1 tbsp Worcestershire sauce
1 tsp fresh thyme leaves, finely chopped (or 1/2 tsp dried thyme)
1 tsp fresh rosemary, finely chopped (or 1/2 tsp dried rosemary)
1 bay leaf (optional)
1 tsp kosher salt, plus more to taste
1/2 tsp freshly ground black pepper, plus more to taste
2 tbsp all-purpose flour
1 cup (240 ml) beef or lamb broth
1/2 cup (120 ml) dry red wine (or substitute with an additional 1/2 cup broth)
1 cup (140 g) frozen peas (no need to thaw)
1/2 cup (70 g) frozen corn kernels (optional)

For Assembly and Garnish

2 tbsp grated Parmesan cheese (optional, for a golden, savory crust)
1 tbsp unsalted butter, cut into small cubes (optional, for dotting on top)
2 tbsp chopped fresh parsley, for garnish (optional)

Step-by-Step Instructions

Step 1: Preheat the oven and prepare your baking dish

Preheat your oven to 400°F (200°C) with a rack in the middle position. Lightly grease a 2-quart (about 2-liter) baking dish with butter or a little olive oil. A 9-inch square dish or similar-sized oval or rectangular casserole works well.

Gather and measure all ingredients. Dice the onions, carrots, and celery; mince the garlic; chop the herbs; and peel and chunk the potatoes. Having everything ready will make the process smooth and enjoyable.

Step 2: Cook the potatoes for the topping

Place the peeled, chunked potatoes in a large pot and cover with cold water by about 1 inch. Add a generous pinch of salt (about 1 tsp). Bring to a boil over high heat, then reduce to a gentle simmer.

Cook until the potatoes are very tender and easily pierced with a fork, about 15–18 minutes depending on the size of the chunks. While the potatoes cook, you can start the lamb ragout to save time.

When the potatoes are done, drain them thoroughly in a colander and let them sit for 2–3 minutes to steam off excess moisture. This helps you get fluffy, not watery, mashed potatoes.

Step 3: Make the buttery mashed potato topping

Return the drained potatoes to the still-warm pot. Add the 4 tbsp butter, warm 1/2 cup milk, and sour cream (if using). Mash with a potato masher or ricer until smooth and creamy. If you prefer a looser mash, add a splash more milk.

Stir in the egg yolk, 1 tsp salt, and 1/4 tsp pepper. The egg yolk helps the top brown beautifully and adds richness. Taste and adjust seasoning as needed.

Set the mashed potatoes aside, covered, while you finish the lamb ragout. They will firm up slightly as they cool, which makes them easier to spread or pipe on top of the filling.

Step 4: Brown the lamb and build flavor

While the potatoes are cooking, heat 2 tbsp olive oil in a large, deep skillet or sauté pan over medium-high heat. Add the ground lamb and cook, breaking it up with a wooden spoon, until well browned and no longer pink, about 6–8 minutes.

If there is a lot of excess fat in the pan, spoon off a bit, leaving about 1–2 tbsp for flavor. Add the diced onion, carrots, and celery. Cook, stirring occasionally, until the vegetables soften and the onion turns translucent, about 6–8 minutes.

Add the garlic and cook for 1 minute more, just until fragrant. Stir in the tomato paste and cook for another 1–2 minutes to caramelize it slightly; this deepens the flavor of the filling.

Step 5: Thicken and simmer the lamb and vegetable ragout

Stir in the Worcestershire sauce, thyme, rosemary, bay leaf (if using), 1 tsp salt, and 1/2 tsp pepper. Sprinkle the 2 tbsp flour evenly over the mixture and stir well to coat the meat and vegetables. Cook for about 1 minute to remove the raw flour taste.

Pour in the red wine (or extra broth), scraping up any browned bits from the bottom of the pan. Let it simmer for 2–3 minutes until slightly reduced. Add the broth, stirring to combine. Bring to a gentle simmer and cook for 8–10 minutes, or until the mixture is thick and saucy but not soupy.

Stir in the frozen peas and corn (if using). Taste and adjust seasoning with additional salt and pepper as needed. Remove and discard the bay leaf. The filling should be rich, savory, and well-seasoned, with a gravy-like consistency.

Step 6: Assemble the shepherd’s pie

Transfer the hot lamb and vegetable ragout to your prepared baking dish, spreading it evenly into all corners. You want a fairly level surface so the potato topping sits nicely.

Dollop the mashed potatoes over the filling in large spoonfuls, then gently spread them to the edges using a spatula. Try to fully seal the filling underneath the potatoes to prevent bubbling over the sides.

If you like a more decorative finish, you can pipe the potatoes on with a piping bag and large tip, or use a fork to create ridges and swirls—these will brown beautifully in the oven. Sprinkle the top with grated Parmesan and dot with small cubes of butter if using.

Step 7: Bake until golden and let rest

Place the assembled shepherd’s pie on a rimmed baking sheet (to catch any potential drips) and bake in the preheated 400°F (200°C) oven for 25–30 minutes, or until the filling is bubbling around the edges and the potato topping is lightly golden in spots.

If you want deeper browning, switch the oven to broil for the last 2–3 minutes, watching very carefully so it does not burn.

Remove from the oven and let the shepherd’s pie rest for 10–15 minutes before serving. This helps the layers set slightly, making it easier to scoop neat portions. Garnish with chopped fresh parsley, then serve warm.

Pro Tips

Choose the right potatoes: Floury potatoes like Yukon Gold or Russet mash smoothly and give a fluffy, creamy topping that browns well.
A dry mash is a good mash: Let the potatoes steam dry after draining before adding butter and milk. Excess water makes the topping loose and less flavorful.
Do not rush the browning: Let the lamb brown well and the tomato paste cook a bit; this caramelization adds big flavor to the ragout.
Control the consistency: The lamb filling should be thick and saucy, not soupy. If it seems too thin, simmer uncovered for a few extra minutes to reduce.
Make it pretty: Use a fork to create ridges and peaks in the mashed potatoes—these high points crisp and brown, giving great texture and a beautiful look.

Variations

Cottage Pie (with Beef): Substitute the ground lamb with ground beef for a classic cottage pie. All other ingredients and method remain the same.
Sweet Potato Topping: Replace some or all of the white potatoes with sweet potatoes for a slightly sweeter, more colorful twist. Reduce the milk slightly, as sweet potatoes are naturally moister.
Extra-Cheesy Crust: Mix 1/2 cup grated Cheddar into the mashed potatoes and sprinkle an additional 1/4 cup on top before baking for a richer, cheesier finish.

Storage & Make-Ahead

To make ahead, assemble the shepherd’s pie completely, let it cool to room temperature, then cover tightly and refrigerate for up to 24 hours before baking. When ready to bake, place the chilled dish in a cold oven, then set the oven to 400°F (200°C) and bake until heated through and golden, adding 10–15 minutes to the baking time if needed.

Leftovers keep well: cool completely, cover, and refrigerate for up to 3–4 days. Reheat individual portions in the microwave or rewarm the whole dish in a 350°F (175°C) oven until hot in the center. To freeze, wrap the assembled (unbaked) pie tightly in foil and freeze for up to 2 months. Thaw overnight in the refrigerator, then bake as directed, adding extra time as needed until piping hot.

Nutrition (per serving)

Approximate values per serving (1 of 6): about 560 calories, 32 g protein, 34 g fat, 31 g carbohydrates, 4 g fiber, and 950 mg sodium. Values will vary based on specific ingredients, brands, and any optional add-ins you use.

Classic Shepherd’s Pie with Buttery Mash Topping