Choripán

Steps

1. chop10 min
   by knife, not machine
   parsley leaves + garlic + oregano, chopped fine on a board — a blender bruises the parsley and emulsifies the oil into a dull green paste; chimichurri is a suspension of distinct particles in oil and vinegar, and you can see the difference in the jar
2. infuse30 min
   room temperature, uncovered
   chopped herbs + garlic + red wine vinegar + 1 tsp salt + red pepper flakes + warm water first, left to sit 10 minutes so the salt and vinegar soften the garlic's raw edge, then + olive oil = chimichurri; adding the oil last keeps the vinegar in contact with the aromatics instead of sealing them off, and the full 30-minute rest is what turns it from chopped salad into sauce
3. dice10 min
   fine, even dice
   onion + tomato (seeds and jelly discarded) + red bell pepper + 1 tbsp olive oil + 1 tsp vinegar + remaining salt + black pepper = salsa criolla; seeding the tomato matters because its liquor will otherwise weep out and turn the bread to pulp under the sausage
4. rest30 min
   room temperature
   chorizo criollo, out of the fridge and left whole — fridge-cold sausage forces you to cook the outside hard to reach the middle. Use fresh, unsmoked Argentine chorizo only: cured Spanish chorizo is already cooked and will simply dry out on the grate, and loose Mexican chorizo has no casing to hold it together. Do not score, prick or salt the links; the casing is a pressure vessel that keeps the rendering fat inside the meat, and salt on the outside draws moisture to the surface and toughens it
5. barbecue35 min
   two-zone fire, sausages over the cooler side, medium coals
   chorizo, banked away from direct coals and turned every 6 or 7 minutes so no face stays hot long enough to blister. This is the long part and it is the point of the dish: the fat inside has to melt and baste the meat before the casing crisps. Rushing it over direct heat boils the fat into steam, the membrane splits, the juices fall into the coals and you are left with a dry link and a grease fire
6. grill15 min
   moving to the hot zone, turning often
   chorizo, over direct heat to finish and colour, until the casing is taut, mahogany and lightly blistered and the centre reads 160°F / 71°C. Argentine parrilla practice runs to about 55 minutes total, far longer than the 20 minutes most English-language recipes give — the temperature and the rendered, no-longer-pink interior are the real target, not the clock
7. score3 min
   off the heat, sausages just cool enough to hold
   chorizo, split lengthwise about three-quarters of the way through so each link opens flat but stays in one piece — this is the mariposa cut, and it gives you twice the surface for the fire without letting the halves curl apart in the sandwich
8. char5 min
   hot zone, cut face down, unmoved
   opened chorizo, pressed flat on the grate until the exposed interior takes a dark crust; leaving it undisturbed is what builds the char — lifting to check every 30 seconds tears the fibres off and leaves them on the bars
9. toast4 min
   cool side of the grate, cut face down
   French rolls, split and buttered on the inside, warmed until the crumb is dry and the cut face is lightly gold. The butter and the toast form a fat barrier so the chimichurri sits on the bread instead of soaking through; soft rolls and ciabatta collapse under the sauce and are the wrong bread for this
10. top3 min
    served immediately, standing up
    toasted roll + chimichurri brushed onto the bread + charred chorizo cut-side up + salsa criolla + a final spoon of chimichurri over the top, 4 to 6 tbsp of sauce in total per sandwich. Choripán is the first thing off the parrilla at an asado, handed out while the beef is still cooking — it is meant to be eaten hot, in hand, before the sauce has time to reach the bottom crust