Essentially a meaty gravy topped with mashed potatoes in pie form, this shepherd's pie is rich and savory, hearty and filling, warm and comforting and plenty of other things all wrapped into one.
Preheat oven to 325ºF. Line a roasting pan with foil and place the lamb shoulder on top.
Drizzle the lamb with olive oil and sprinkle with sea salt on both sides.
Roast the lamb for around 3-4 hours in the preheated oven. You’ll know it’s ready when it smells fantastic, it’s golden brown and the meat separates easily from the bone.
When it's done, let it cool.
When the lamb has been cooking for around 3 hours, begin preparing the pie. First, boil the potatoes in salted water until soft (around 20 minutes). Reserve 2 cups of the water from boiling the potatoes and drain the rest.
Mash the potatoes using a fork.
Add ½ cup of shredded cheddar cheese, 1 tablespoon of butter and salt, to taste. Mix well.
Heat a skillet to medium-low heat and add the other tablespoon of butter. Sauté the onions with dried rosemary for around 20 minutes, or until starting to brown. Set aside.
When the lamb has cooled, shred the meat with two forks and cut the skin into small pieces.
Pour 2 cups of boiling water (you can use the reserved liquid from the potatoes) into the baking tray to remove the grease and all cooking juices from the lamb. Pour some of this liquid over the lamb’s meat (just enough to moisten it), and mix it with the onions to complete the filling. Season the filling, to taste.
Preheat oven to 400ºF. To make the pie, grease a pie plate with olive oil and cover with ½ of the mashed potatoes. Use your hands to spread it evenly, leaving a bit of a border.
Add the lamb filling over top of the potatoes.
Cover with the other half of the potatoes and spread it with your hands to cover the shredded lamb. Spread the other ½ cup of shredded cheddar cheese over the pie.
Use a fork to make a rim around the pie.
Bake for about 30 minutes in the preheated oven - until golden brown and bubbly. Let cool for about 10 minutes.
Serve and enjoy!
Notes
Refrigerate: Store any leftovers in the fridge for up to 4 days.
Freeze: You can also store the pie in the freezer for up to a few months, well-covered, but let it cool first.
Reheat: You can reheat the refrigerated shepherd's pie in a 350ºF oven until heated all the way through or in the microwave. You can reheat the frozen pie directly in the oven. You can also thaw it in the fridge first and then bake--this option will result in more even heating.