1. Preheat oven to 350⁰F.
2. In a pan, heat fennel seeds over high heat for 2 minutes. Set aside.
3. Boil potatoes in salted water, then drain and mash with a fork. Add toasted fennel seeds and mix.
4. In a bowl, combine the potato mixture, parsley, and tuna. Season with salt and pepper.
5. Cut each brick sheet in half. Fold the rounded edge over the straight edge to form a rectangle.
6. Place the filling at one end, then fold several times from one edge to the other, maintaining a triangle shape.
7. Place on a baking sheet lined with parchment paper.
8. Bake for 10 minutes.
9. Remove from oven and serve.