Causa Limeña

Causa is built from papa amarilla, the yellow Peruvian potato, boiled, pressed and worked with lime juice, oil and ají amarillo paste until it is dense, smooth and pale orange, then layered in a mould around a filling - chicken or tuna with mayonnaise most commonly, or crab, prawn, avocado - and turned out to be eaten cold, usually as a starter. It is a dish that depends entirely on the potato: Peru has thousands of native varieties, and the amarilla has the floury texture and the flavour this needs. The name attracts stories, the most repeated being that it was sold to raise money for the army during the War of the Pacific - por la causa, for the cause - which is almost certainly folk etymology, since causa more plausibly derives from the Quechua kausay, meaning sustenance or life. Modern versions run to elaborate presentations.

What you actually see

• The potato base - papa amarilla worked with lime, oil and ají amarillo.
• The layers - filling packed between potato and turned out of a mould.
• The colour - the pale orange the ají gives the mash.
• The name - probably from Quechua kausay, not the war-fundraising story.

When to go

Year-round, served cold, generally as a starter. Available everywhere from market counters to formal restaurants.

Honest expectations

Ají amarillo is mild but present; some versions are hotter. Mayonnaise-heavy fillings sit poorly in heat - eat it where turnover is high. The elaborate restaurant versions bear little resemblance to the homely original.

Nearby

Lima's markets and menú restaurants serve it daily; Surquillo and the Mercado Central are good places to try it.