"It's impossible to compare pebre with chancho en piedra (...). The flavour of chancho en piedra comes from the stone and the grinding. It has nothing to do with pebre."
Interview with Carmen G Larraín, in The Pleasing Pot, by Sonia Montecino, ed Catalonia, 2005.
For any Chilean, the foreign intention of joining the pebre and chancho en piedra (literal translation: pork on stone) under the same definition must be as annoying as being confused with your twin brother all the time. It's undeniable that there are similarities, but when one starts to go into detail about it, one discovers the moles and expressions that distinguish one brother from the other one. In the chancho en piedra the ingredients are ground with the mortar, which, obviously, has to be a stone one. Rock salt is ground first, along with garlic, onion and tomato. It's seasoned with lemon, oil and a bit of coriander, but never with ají (chili). On the other hand pebre is finely chopped onion, garlic, coriander and yes, ají. Just sometimes it has tomatoes (chopped, not ground), some other it has merkén (Southern Pebre), parsley (Green Pebre) or ají cacho de cabra, which transforms it into fury made sauce and makes brave whoever adopts it at his table.
So close in appearance, so far in etymology. It is believed that the word pebre comes from Catalan, where it means pepper. The chancho en piedra case is more complicated. Some versions maintain that "chancho" (pork) comes from the porky or filthy way of the spatula used to grind the ingredients, and "piedra" (stone) because of the stone used to mash this paste. A different version says that "chancho en piedra" is an alteration from "chanca en piedra". In Chile, Peru and Argentina, "chanca" is synonym of crushed. "Chancar" comes from the Quechua "chamgay" and it means to mash or to crush. What is clear is that "chancho en piedra" is a confusing assignment, because it fills our expectations with pork. However, one of the closest flavors to meat is tomato, one of the the fifth flavor's representative, an umami agent.
In spite of their different compositions they both come along for identical occasions: meat, choripan (chorizo with bread), empanadas (pasties), or even bread on its own. Sauces in general tend to be optional, but pebre and chancho en piedra are, with no doubt, essential. They mutate the flavor completely making it Chilean, and it's such a clear taste, so distinctive, that it allows you to visit Chile from any plate containing it, no matter how far from.