Slice the potatoes uniformly to ensure even cooking.
Dice the carrots into consistent pieces for balanced flavor and texture.
Chop the onions evenly.
Chop the celery into similar-sized pieces.
Preheat a large pan until it's smoking hot.
Carefully place the lamb pieces into the pan. Sear until all sides are browned, locking in the juices and creating a rich caramelization.
Start with a layer of thinly sliced potatoes at the bottom of your baking dish.
Add a layer of seared lamb pieces.
Add a layer of the seasoned vegetables (carrots, onions, celery).
Repeat the layering process, finishing with a top layer of potato slices.
Generously brush the top potato layer with melted margarine.
Pour enough stock over the assembled hotpot to come up to the level of the top potato layer.
Preheat your oven to 160°C (325°F).
Place the assembled hotpot into a covered baking dish.
Cover the dish with a lid or aluminum foil.
Bake in the preheated oven for approximately 2 hours.
After 2 hours, uncover the dish.
Bake for an additional 30 minutes, or until the top potato layer becomes beautifully golden and crispy.