Ají Criollo

The oil went in too fast or the blender was stopped when it was added. Emulsions form only when oil enters a moving liquid in a thin stream. To rescue it, put a spoonful of queso fresco and a splash of evaporated milk in a clean blender and pour the split sauce into that slowly while it runs.

Four tablespoons of jarred ají amarillo paste replace the six fresh chillies and skip the deveining and boiling entirely, but the paste is already concentrated and hotter, so leave out the ají limo the first time and add it only after tasting. Frozen whole ají amarillo, if you can find it, behaves exactly like fresh. Jarred paste is sold in Latin American shops and online.

Five days in a sealed jar in the fridge, though the colour dulls from day two and the herbal note fades first. It freezes well for three months, which is the better option if you are making a full batch for two people. Use a clean spoon each time, because the cheese and milk make it spoil faster than a chilli sauce without dairy, and stir it before serving, since it thickens as it chills.

Salsa criolla is not a sauce at all but a salad of thinly sliced red onion with lime, chilli and coriander. Ají de huacatay pushes the herb to the front and often uses soaked cracker or bread for body, while this version leans on cheese and oil and keeps the huacatay as an accent. The practical difference is texture: ají criollo is blended smooth and creamy, while salsa criolla is chopped and raw.

Roast or rotisserie chicken above all, plus anticuchos de corazón, boiled potatoes, fried cassava and salchipapas, always in a small bowl per person rather than poured over the plate. It is a condiment applied at the table, never a cooking medium. It also goes well next to causa limeña, where a spoonful lifts the cold potato layers.