Preheat the oven to 375 degrees F (190 degrees C).
Halve and thinly slice the Potato (4).
Heat Vegetable Stock (2 cup) and when it's boiling, add the Swordfish Fillet (1) with its skin removed, Salt (1 pinch), Ground Black Pepper (1 pinch) and Fennel Pollen (1 pinch). Braise for about 10-20 minutes, depending on the thickness of the fish.
Heat a skillet and add the Butter (2 tablespoon).
When the butter starts to brown, add sliced potatoes, Salt (to taste), Ground Black Pepper (to taste) and Fennel Pollen (1 pinch). Cook for about 7 minutes over medium-low heat, stirring occasionally.
Add Zucchini (1) and cook for about 6 minutes more, with a dash more salt, pepper, and fennel pollen.
Add Garlic (1 clove) and cook for 1 minute more. Taste and adjust seasoning if needed.
Divide Pie Crust (1) into 3 equal pieces and roll them out. Place them on a baking sheet.
Divide potato mixture between the three crusts and spoon onto one side. Top with Tomato (1) and the fish. Sprinkle with a bit more salt, pepper, and fennel pollen.
Fold the non-topped side of the crust over the fish and veggies. Press edges down and crimp to seal with a fork. Pierce the top a few times with the fork.
Beat the Egg (1) and brush the pastry with it. Sprinkle with Coarse Sea Salt (to taste).
Bake for 25-30 minutes on a rack placed in the top third of the oven.