Boil the potatoes in water with curry (¼ tsp), ¼ tsp nutmeg, salt and 1 Tbsp olive oil, and optional turmeric.
Finely chop the leeks and onion. Sauté the onion for 1 minute, add the leeks and continue sautéing for another 3 minutes.
In a bowl, add the potatoes, leeks, onion, remaining nutmeg (¾ tsp), salt and pepper, and mash the potatoes, mixing all the ingredients at the same time.
Lightly oil the sheets on one side, and place them stacked on top of each other. Cut them, all together, into 5 equal strips (with 4 deep incisions). Cut the leaves widthwise (i.e. the length of each piece is equal to the smallest side of the original sheet).
Put a full tablespoon at the lower part of each piece of sheet, and roll relatively tightly upwards. Brush with some olive oil the end of the sheet so that it sticks well and does not unroll. Line a baking pan with parchment paper and put the rolls very close to each other, but not too close. If you want, lightly brush them with some olive oil.
Bake in a preheated oven at 200°C/392°F in the middle-bottom rack for 40 minutes or until golden brown.
Serving
Serve warm as an appetizer. For the presentation, you can serve them with any kind of green salad you like.
Notes
To save time:
Cut the potatoes into bite-sized pieces so that they boil faster.