Prepare the mashed potatoes: Peel the potatoes and cut to medium cubes. Add to large pot and cover with fresh water. Season with sea salt and bring to a boil, reduce heat to low, cover up and keep for 20 minutes.

Preheat oven to 200°C/400°F with a rack in the center.

While potatoes cook, prepare the filling: With a sharp knife, finely chop the onions and roughly chop the spinach.

In a large wide skillet, add the oil and swirl the pan to evenly coat its base. Over high heat, add the minced meat and brown until no pink remains. Stir in the onions and cook for 2 minutes, then follow with the chopped spinach; and keep on sauteing until the leaves wilt. Season with sea salt and a pinch of both cinnamon powder and freshly grated black pepper. Set aside.

Drain the potatoes and mash well using a potato masher, add the butter, grated Parmesan, grated nutmeg, crushed black pepper and sea salt, and give a quick stir. Add the heavy cream and mix well to homogenize the mash. Set aside.

To assemble: Grease a large baking dish and evenly spread half of the mashed potatoes over it. Spread the filling of meat and spinach on top. Gently spread the remaining mashed potatoes on top to cover the meat filling, making sure to keep everything neat. A small trick worth mentioning while adding the top layer is to dip a spoon in water and gently spread the mashed potatoes to avoid messing up the layer of mashed potatoes with the meat filling.

Beat the egg with a drop of vinegar and generously brush the top with the egg; add the breadcrumbs evenly and bake

Bake for 20-25 minutes to a golden color. Let the pie rest for 10 minutes, allowing the souffle to cool down a bit and thicken just up slightly. Use a metal spatula to score and scoop pretty portions onto individual plates. Happy eating!