Ingredients :

• Potatoes — Charlotte or Monalisa preferably. They hold up better during cooking and won’t turn into mash after 35 minutes in the oven. Cut them into 3 to 4 mm slices — a mandoline is perfect, but a knife works too if you are consistent.
• Poultry Chorizo — It comes in mild and smoked versions — go for the smoked one; it gives the dish the most character. Make sure to remove the skin before cutting: it stays tough during cooking and ruins the texture. In thin slices, it melts better and flavors the sauce more.
• Diced Tomato Pulp — A good quality can does the job without any fuss. If you want more body, drain the pulp slightly before adding it — the sauce will be less liquid and the layers will hold together better when sliced.
• Grated Gruyère — Not a “pizza” or “4-cheese” blend. Just Gruyère, period. If possible, grate it at the last moment; it melts more evenly and browns better — it’s what gives that cracked crust you scrape off the edges of the dish.