In a large skillet over medium-high heat, heat up the oil and add the ground lamb, crumbling in with a meat chopper or cooking utensil. Add the onions, celery, and carrots, and cook until the meat is no longer pink.
Add the flour and the tomato paste to the meat mixture and stir thoroughly. Cook for an additional 1-2 minutes. Add the bay leaf and the broth; stir to combine. Cover with a lid and cook for 10 minutes on low heat, stirring occasionally.
Meanwhile, peel and cut the potatoes into pieces. Place the potatoes in a pot and cover them with salted water. Bring to a boil and cook for about 10 minutes or until potatoes are soft. Drain the water and put the potatoes back on the stove to steam them. Pour in the milk, add the butter and a bit of nutmeg, and mash until desired consistency.
Preheat your oven to 350°F.
Remove the meat filling from the heat, add salt and pepper to taste. Remove the bay leaf and spread the meat mixture evenly into an 8x8-in. or 9x9-in. baking dish. Taste the mashed potatoes and adjust seasoning if needed. Spread the potatoes evenly over the meat filling and make a pattern with a fork, if desired.
Bake for 20-25 minutes until potatoes are golden brown and the filling is bubbly.
Notes
Frying the tomato paste a bit will help to remove the bitterness.
For mashed potatoes, I always cut the potatoes a bit smaller, so they cook faster. They will be mashed later, so it doesn´t matter.
After draining the potatoes, use medium heat and leave the potatoes on the stove for around 10 seconds at a time. Shake the pot and put it back on the stove. Repeat until the water is gone and the potatoes look a bit dusty.
You can add cheese like cheddar on top or some butter flakes to make this even more awesome.
If lamb is not your thing or is not readily available where you live, you can use this same recipe and substitute ground beef, ground chicken, or ground pork to make a Cottage Pie instead!
Can I make this ahead?
Yes, you can cook and assemble ahead. Cover tightly and leave in the fridge for up to one day. Bake before serving. It will need to bake longer when chilled.
Can I freeze Shepherd’s Pie?
Yes! Assemble the pie as directed in the recipe but do not bake it. Make sure the pie is cooled completely, then cover it well with cling film and freeze it. It is good for up to two months. Defrost it in the fridge overnight, then cook as per the recipe.
Can I make more?
Totally, just double the ingredients and use a bigger casserole pan.