Classic Irish Shepherd's Pie with Guinness Mashed Potatoes
Shepherd's Pie
This is my take on a classic Irish shepherd's pie—warm, comforting, and built around robust minced lamb and a velvety Guinness-infused mashed potato crust. It’s the kind of dish that smells like Sunday afternoon and feeds a crowd with very little fuss.
The filling is savory and well-seasoned with onion, carrots, celery, thyme, and a hit of Worcestershire; a splash of Guinness adds depth and a hint of caramelized maltiness. The mashed potatoes are whipped until silky, folded with butter and milk, and finished with a touch of Guinness for extra character.
It’s perfect for weeknight dinners or a cozy weekend meal. Assemble ahead and bake when you’re ready — the top crisps to a beautiful golden crown while the filling bubbles gently beneath. You’ll love serving this straight from the oven.
Ingredients
- 1.5 lb Ground lamb
- 1 pieces Yellow onion, finely chopped
- 2 pieces Carrots, diced
- 2 pieces Celery stalks, diced
- 3 pieces Garlic cloves, minced
- 2 tbsp Olive oil
- 2 tbsp Tomato paste
- 2 tbsp All-purpose flour
- 1 cup Guinness stout
- 1 cup Beef or lamb stock
- 1 tbsp Worcestershire sauce
- 1 tbsp Fresh thyme leaves, chopped
- 1 cup Frozen peas
- 1 tsp Kosher salt
- 1 tsp Freshly ground black pepper
- 2 lb Russet potatoes, peeled and cut into chunks
- 6 tbsp Unsalted butter
- 1/2 cup Whole milk
- 2 tbsp Sour cream (optional, for extra creaminess)
- 2 tbsp Fresh parsley, chopped (for garnish)
Instructions
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Preheat the oven to 400°F.
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Place potatoes in a large pot, cover with cold water and 1 tsp salt, bring to a boil and simmer until tender, about 15–18 minutes. Drain well.
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While potatoes cook, heat olive oil in a large skillet over medium-high heat. Add onion, carrots, and celery and cook until softened, about 6–8 minutes.
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Add garlic and cook 30 seconds more. Push the vegetables to the side, add the ground lamb and brown, breaking it up with a spoon, about 6–7 minutes. Drain excess fat if needed.
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Stir in tomato paste and flour and cook 1–2 minutes to remove the raw flour taste.
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Pour in 1/2 cup Guinness and scrape up any browned bits from the pan. Add the stock, Worcestershire, thyme, frozen peas, salt, and pepper. Bring to a gentle simmer and cook until slightly thickened, about 8–10 minutes. Remove from heat.
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For the mash: add 1/4 cup Guinness (or reserved from the bottle), butter, milk and sour cream (if using) to the drained potatoes. Mash until smooth and season to taste with salt and pepper.
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Spoon the lamb filling into a 9x13-inch (or similar) baking dish, then spread or pipe the mashed potatoes over the top. Dot with the remaining 1 tbsp butter if you like extra browning.
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Bake until the top is golden and the filling is bubbling at the edges, about 20–25 minutes. For a crispier top, place under the broiler for 1–2 minutes—watch carefully.
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Let the pie rest 5–10 minutes before serving. Garnish with chopped parsley and serve hot.
Tips & Notes
- Brown the lamb well for added depth—those caramelized bits flavor the whole pie.
- If the filling looks thin before baking, simmer a few minutes longer to reduce; you want it saucy but not watery.
- Make ahead: assemble the pie and refrigerate for up to 24 hours; bring to room temperature before baking and add a few extra minutes to the cook time.
- Swap lamb for ground beef to make a cottage pie variation, and adjust seasoning to taste.