he Argentine hot dog, known as choripán or simply pancho, is a popular street food consisting of grilled chorizo sausage served on crusty bread, typically topped with chimichurri sauce. Unlike American hot dogs, it focuses on high-quality beef/pork sausage, often split lengthwise, paired with fresh toppings like salsa criolla. 
Key Aspects of Argentine Hot Dogs:
Choripán (The Classic): Features a grilled chorizo sausage (pork or beef) inside a crunchy French bread roll (pan francés).
Key Toppings: The defining, essential topping is chimichurri, a sauce made from parsley, garlic, oregano, olive oil, and vinegar. Another popular option is salsa criolla (diced tomatoes, onions, and peppers).
Panchos: A more standard hot dog style, often with thinner sausages, served with simple toppings like mayo, mustard, or salsa.
Where to find it: It is a staples at football matches, street food stalls, and as a popular starter at barbecues (asados). 
How to Prepare (Choripán Style):
Grill the chorizo sausages over medium heat for 10-15 minutes until charred.
Split the sausages lengthwise and grill the inner side for a minute.
Toast the bread, then place the sausage inside.
Top generously with fresh chimichurri.