Causa rellena is a Peruvian dish of chilled, lime-seasoned mashed potatoes layered with fillings; this version pairs them with shrimp, avocado, and tomato. Ají amarillo adds the fruity warmth associated with the potato mixture, while the creamy avocado and bright tomato balance it. Recipes and shapes vary by region and family, so you can serve these as individual molded cakes or assemble them in one dish.
Ingredients
- 2½ lb (1.1 kg) yellow potatoes, such as Yukon Gold, scrubbed and cut into even chunks
- 1½ tsp (9 g) fine salt for the potato cooking water, plus more to season
- 2 tbsp (30 ml) fresh lime juice, plus 1 tsp (5 ml) for the avocado
- 2 tbsp (30 g) ají amarillo paste, or to taste
- 3 tbsp (45 ml) neutral oil, such as vegetable or avocado oil
- ¼ tsp ground black pepper
- 12 oz (340 g) raw medium shrimp, peeled and deveined
- 1 tsp (5 ml) neutral oil for cooking the shrimp
- ⅓ cup (75 g) mayonnaise
- 1 tbsp (15 ml) lime juice for the shrimp filling
- 1 small celery stalk, finely diced, about ¼ cup (25 g)
- 2 ripe but firm avocados, about 10 oz (280 g) flesh
- 1 medium ripe tomato, about 5 oz (140 g), seeded and diced
- 2 tbsp (8 g) chopped cilantro, plus a little extra for garnish
- 1 tbsp (15 g) finely diced red onion, rinsed and patted dry
- 6 small lettuce leaves, for serving (optional)
Instructions
- Cook the potatoes. Put the potato chunks in a large saucepan and cover with cold water by about 1 inch (2.5 cm). Add 1½ teaspoons salt. Bring to a boil, then lower the heat to maintain a steady simmer. Cook for 20–25 minutes, until a thin knife slides into the largest piece without resistance. Drain thoroughly. Let the potatoes sit in the colander for 2 minutes so excess steam escapes; wet potatoes make a loose, harder-to-mold causa.
- Make the potato mixture while the potatoes are hot. Pass the drained potatoes through a ricer or mash them thoroughly with a potato masher in a large bowl. Work out lumps while they are still warm, but do not use a blender or food processor, which can turn potatoes gluey. Mix in the 2 tablespoons lime juice, ají amarillo paste, 3 tablespoons oil, and black pepper. Taste carefully and add salt or a little more lime if needed. The mixture should be savory, gently tangy, and flexible enough to press into a mold without crumbling. If it seems dry, mix in oil 1 teaspoon (5 ml) at a time.
- Cook the shrimp. Pat the shrimp dry and heat 1 teaspoon oil in a skillet over medium heat. Add the shrimp in a single layer and cook for about 2 minutes on the first side and 1–2 minutes on the second, turning once. Check the thickest shrimp with a food thermometer: the USDA FSIS safe minimum internal temperature for shrimp is 145°F (63°C). The flesh should also be opaque. Transfer to a plate and cool promptly. Once cool, chop into small pieces.
- Mix the shrimp filling. Stir the mayonnaise and 1 tablespoon lime juice together in a bowl. Fold in the chopped shrimp and celery; season with a small pinch of salt if needed. Keep the filling refrigerated while you prepare the remaining ingredients. It should hold together when spooned but not be runny. If the shrimp released liquid as it cooled, drain it before mixing so the filling does not soften the potato layers.
- Prepare the avocado and tomato. Cut the avocados into small slices or cubes and gently toss with 1 teaspoon lime juice. Seed and dice the tomato, then blot it with a paper towel if it is particularly juicy. Combine the tomato with the cilantro and red onion. Keeping these components separate until assembly preserves their color and texture.
- Shape the causa. Lightly oil six 3-inch (7.5 cm) ring molds, or use a small straight-sided cup lined with a strip of parchment. Set the molds on a parchment-lined tray. Divide the potato mixture into 18 portions. Press one portion into the bottom of each mold to make a compact layer about ½ inch (1.25 cm) thick. Add a layer of avocado, followed by a spoonful of shrimp filling and a little tomato mixture. Leave a narrow border around the edge so the filling does not spill out. Top each with another portion of potato and press gently, then add a final potato portion as a neat top layer. Smooth the surface without crushing the filling. If using a cup, invert each portion onto a plate and lift the cup away carefully.
- Chill and serve. Cover the cakes loosely and refrigerate for 30 minutes so they firm up and release more cleanly from the molds. Run a thin knife around each ring, lift the mold straight up, and transfer the cakes to plates. Garnish with cilantro and serve cold or cool, not frozen. The full chilling time is included in the total time above.
Tips
- Choose potatoes that mash smoothly. Yellow potatoes are creamy and hold their shape well. Russets also work, though they can produce a drier mixture; add oil gradually until the potato dough presses together. Avoid waxy new potatoes, which may stay lumpy when mashed.
- Ají amarillo paste is worth seeking out. It is sold in many Latin American grocery stores and some larger supermarkets. If unavailable, use 1 tablespoon (15 g) smooth yellow or orange bell-pepper purée with a small pinch of cayenne. This gives color and mild heat, but it will not reproduce the paste’s distinct fruity flavor.
- Keep the layers tidy. Drain the potatoes well, seed the tomato, and cool the shrimp before mixing it with mayonnaise. If the potato mixture sticks to your hands, lightly oil your fingertips rather than adding lots of extra oil to the dough.
- Make the components ahead, not the avocado. Cook and chill the potatoes and shrimp filling separately up to a day ahead. Cut and season the avocado shortly before assembling, since it darkens over time. A ring mold makes even portions, but a small bowl or ramekin lined with parchment can serve as a practical substitute.
Serving Suggestions
Serve one molded causa per person as a cool starter or a light main course. Set each cake on a lettuce leaf if you like a little crispness beneath the soft potato, and add extra lime wedges for guests who prefer a sharper finish. A small sprinkle of cilantro or a few thin slices of red onion make a simple garnish; avoid piling on too much, since the layers are the focus.
For a fuller meal, pair the cakes with a crisp green salad dressed with lime and oil, or serve them alongside grilled vegetables. The potato, shrimp, and avocado make the dish substantial, while fresh greens add crunch. If serving a group, arrange the cakes on a chilled platter and keep it refrigerated until close to mealtime. Put out only what will be eaten soon, then return the rest to the refrigerator rather than leaving the seafood filling at room temperature.
Variations
Make one large causa. For a shared platter, press half of the potato mixture into a shallow dish, spread the avocado, shrimp, and tomato filling over it, then cover with the remaining potato. Chill for 30 minutes or until firm enough to slice. A dish about 8 inches (20 cm) wide works well; use a broad spatula to serve neat portions.
Try a different filling. Cooked flaked fish can replace the shrimp; check that fish reaches 145°F (63°C) with a food thermometer. For a vegetarian version, use cooked green peas or finely chopped, cooked vegetables folded with the mayonnaise, or layer in extra avocado and tomato. Keep juicy ingredients drained so the potato stays firm.
Adjust the heat. Start with 1 tablespoon ají amarillo paste for a milder potato layer and add more after tasting. For extra heat, add a little finely minced fresh chile to the shrimp filling. For a gentler flavor, reduce the paste and add a pinch more salt and lime to keep the potatoes lively.
Change the shape. Ring molds make individual cakes, but you can shape the potato into small rounds with clean hands or use a lined ramekin. If making smaller portions, keep the same general layer proportions and chill them before unmolding. Very thin layers are more likely to crack, so aim for potato layers at least ½ inch (1.25 cm) thick.
Storage and Reheating
Refrigerate causa within 2 hours of preparing or serving it. Keep the cakes covered in an airtight container at 40°F (4°C) or colder. They are at their best within 24 hours, when the avocado and tomato still look fresh; as a cooked seafood-and-potato leftover, they can be refrigerated for 3–4 days if handled safely, though the texture and color will decline. Do not leave them at room temperature for extended serving or storage.
Causa rellena is intended to be served cold, so reheating is usually unnecessary and can make the avocado unpleasant and the potato soft. If you want warm potato, store the potato separately from the shrimp, avocado, and tomato, and reheat only the potato. Reheat cooked leftovers to 165°F (74°C), checking with a food thermometer, then assemble with freshly chilled toppings. Do not freeze assembled cakes: thawing tends to make the potato watery and the avocado mushy.
Frequently Asked Questions
Can I make causa rellena without a ring mold?
Yes. Use a small ramekin, cup, or straight-sided bowl lined with parchment, or shape the layers by hand on a plate. Press the potato gently into an even layer and chill before turning out or serving. A ring mold gives the cleanest edges, but it is not necessary for good flavor.
What does ají amarillo taste like, and can I leave it out?
Ají amarillo has a fruity, peppery flavor and mild-to-moderate heat. You can reduce or omit it if you do not want spice, though the potato will taste less distinctive. Yellow bell-pepper purée with a pinch of cayenne is a practical substitute, but the flavor will be milder and less fruity.
Can I use frozen shrimp?
Yes. Thaw frozen raw shrimp in the refrigerator overnight, or keep it sealed and thaw it under cold running water. Drain and pat it dry before cooking. Cook until opaque and verify that the thickest shrimp reaches the USDA FSIS safe minimum of 145°F (63°C).
Why is my potato mixture sticky or falling apart?
Sticky potatoes are often overworked, especially in a blender or food processor, or mashed after they have cooled too much. Use a masher or ricer and mix only until the seasonings are incorporated. A mixture that falls apart may be too dry or contain excess moisture from poorly drained potatoes; adjust with a little oil if dry, or let it cool and firm before shaping if damp.
Can I assemble the cakes the day before?
You can assemble them up to a day ahead and keep them covered in the refrigerator, but the avocado may darken and the tomato can release liquid. For the freshest appearance, make the potato and shrimp components ahead, then cut the avocado and assemble a few hours before serving. Keep the finished cakes chilled until they are put on the table.
Related
- Peruvian Roast Chicken with Green Aji Sauce
- Peruvian Ceviche Recipe with Lime, Ají, and Sweet Potato
- Peruvian Causa Rellena: A Layered Potato Recipe
More recipes to cook
Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes
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