Salchipapa is the affectionate nickname for a popular street food in many parts of Latin America - a salty, tasty combination of salchicha (hot dog/sausage) and papas fritas (French fries). Kids love salchipapas - they are a comfort food akin to the hot dog in the US. Salchipapas are very popular in Peru and the other Andean countries, where they are often doused with aji sauce and served with slaw. Other countries in South America have incorporated salchipapas into their menu of street food choices, typically adding their own unique sauces and condiments. Choripapas are a variation on the theme - made with chorizo (Mexican-style) instead of hot dogs.
To prepare salchipapas, the hot dogs should be sliced thinly on the diagonal and fried until they are nicely browned and start to curl up a bit. Any kind of french fries works well - I like steak fries and I often save time by starting with frozen ones and either baking or frying them. Serve the fries and hot dog pieces together in a big pile, drizzled with ketchup, aji sauce, and anything else that seems good (mayonnaise, mustard, salsa criolla, etc).