Grilling With Vinegar: Chimichurri Transforms Grilled Summer Squash

I've never been to Argentina, but my wife has, and from Buenos Aires to the Uco Valley through Mendoza, she says there's one constant: barbecue. What we call barbecue (or grilling) in the US is known as asado in most of South America (churrasco in Brazil). The cookouts, done entirely over charcoal or wood embers, are not just weekend picnics, they're an ingrained part of Argentine family culture.

But my wife and I have both been to Ox Restaurant in Portland, Oregon, where Gabrielle and Greg Denton's Argentine-inspired recipes are made with ingredients from the Pacific Northwest and cooked with live wood fire. Grilled flanken-cut short ribs, succulent skirt steaks, house-made chorizo (pork) and morcilla (blood) sausages, even a halibut chop and local oyster mushrooms, are all beautifully touched with smoke—and everything is served with a small bowl of chimichurri on the side. I found myself reaching for another spoonful of chimichurri with every bite, because each mouthful seemed incomplete without it.

Chimichurri starts with minced onions and garlic, bolstered by a bouquet of fresh herbs, typically parsley and oregano, all of which is then combined with red wine vinegar and olive oil. It's an uncooked sauce, essentially half vinaigrette and half herb salad, and its brightness is an ideal contrast to the concentrated carbon from the grill.

Chimichurri likely has Basque origins, and it arrived in Argentina when enclaves of Spanish settlers made their homes there during the 19th century. The piquant sauce is used in much the same way French use persillade, as a condiment and garnish. Whereas persillade is a much tighter version (it has a smaller ratio of oil and vinegar to herbs), the looseness of chimichurri makes it much easier to work with for the less adept cook. The recipe itself is malleable, too—that's the whole point. The Basque name vaguely translates to "mixing varied things together in no particular order," so it's a recipe no one should be afraid to follow... or deviate from. Its versatility allows for personal interpretation. My recipe calls for cilantro for a more fragrant iteration, and chopped jalapeños for a kick, but feel free to omit them if you're into something more restrained yet no less refreshing.

I was initially surprised that chimichurri calls for red wine vinegar. I thought it would discolor the greenery, but considering the ideal destination of the sauce—steak (though try it on fried eggs!)—it makes sense. Most people opt to drink red wine with red meat, a choice that's more about body than color or flavor. Also, I find that red wine vinegar stands up to the potency of the onions and garlic better and has a greater tempering effect than a white wine vinegar would. That's not to say chimichurri doesn't have a bite (it does), but it shouldn't overwhelm whatever you're eating with it.

Here, rather than hitting up the butcher, I decided to grill summer squash and zucchini, as I love how their natural sweetness gets accentuated by the grill, and then top them with chimichurri for a bright and herbal counterbalance. The dish is a great salad of sorts on its own, but it also makes a nice side dish for grilled proteins.

I set up a grill for two-zone indirect cooking by piling all the coals on only half the coal grate. To grill the squash while maintaining some of its firmness, I cut them in half lengthwise, cook them hard over direct heat only on their cut side, and then let them cook a little longer on the cooler side of the grill until just tender.

I then cut the squash into smaller chunks and dress them in the chimichurri while they're still warm, so they soak up all the delicious commingled flavors. They can be eaten warm right away, but the longer you let them marinate, the more intensely the chimichurri expression comes through.

I've even kept them in the fridge overnight and used them as a side for scrambled eggs, or even just put them on toast. It makes me wonder what gauchos eat for breakfast—a little bit of vinegar in the morning will surely wake you up!