①Boil water(excluding ingredients) in a pot, add salt(around 1% of the water), and the potatoes with the skins on. Boil for around 20 minutes. Once cooked, drain them in a colander and let them cool slightly. Peel the potatoes, place them in a bowl, and mash them with a masher. ②Mince the the anchovy fillets(A). ③Sprinkle the cod with salt and let it sit for 15-20 minutes. Pat it dry with paper towels and cut it into around 3 cm wide pieces. ④Heat olive oil in a frying pan, add breadcrumbs, and sauté over medium heat until crispy and the moisture is gone. ⑤In the same frying pan, add the butter(A) and heat over low heat. Once the butter has melted, add all the anchovy fillets(②) and the cod(③), cooking until both sides are browned. ⑥In a bowl, add the potatoes(①), half of the cod(⑤), and all of the anchovy butter sauce(⑤), and mix lightly. ⑦Spread the potato paste(⑥) evenly in a heatproof dish, top with the remaining cod(⑤) and the breadcrumbs(④). Bake in a toaster oven for 6-7 minutes, and finish by sprinkling parsley on top. Done!