Instructions
Follow the steps and taste along the way.
Boil the potatoes
Wash the potatoes, place them in a pot, and cover with 2 l of water. Add 5 g of salt, bring to a boil, and cook for 20–25 minutes, until easily pierced with a knife. Drain and peel while still warm.
Season the potato mixture
Press the warm potatoes through a ricer into a bowl or mash them into a smooth purée with no lumps. Stir in the vegetable oil, ají amarillo paste, 35 ml of lime juice, and 2 g of salt. Mix until the potato mixture is evenly yellow, then leave to cool for about 10 minutes.
Prepare the fillings
Flake the drained tuna with a fork and mix it with the mayonnaise, red onion, cilantro, black pepper, and remaining 1 g of salt. Cut the avocado into thin slices and drizzle with the remaining 10 ml of lime juice.
Layer the causa
Place a round mold about 18 cm in diameter on a serving plate. Press half of the potato mixture into the bottom in an even layer. Arrange the avocado on top, spread the tuna mixture over it, and cover with the remaining potato mixture. Gently smooth the top layer.
Chill and serve
Refrigerate the causa for 20 minutes so the layers can firm up. Carefully remove the mold and cut into four portions. Serve cold; the layers should hold their shape, while the potato mixture remains soft.
