Chris found this recipe recently, in the copy of At Home with Michael Chiarello that he bought me a few years ago. We've made it twice and when he gets home from taking Becky to her first Semi-Formal (well, not her first, but her first with a date), we're going to make it a third time. You can find the recipe on the Napastyle website, and here's a direct link: Grilled Gaucho Steak with Chimichurri Sauce but it's not exactly the same as in the cookbook, which I'm going to give you now.
Grilled Gaucho Steak with Chimichurri Sauce
1 bunch fresh Italian parsley, finely chopped (I didn't bother with this, let the food processor do the work)
2 bay leaves, broken into small pieces (honestly, I never got this part; I thought you're not supposed to eat bay leaves so I just leave them out)
6 cloves garlic, minced (again, through them whole into the processor)
1.5T Spanish paprika (don't have spanish so I've use Hungarian hot/mild combo and/or smoked paprika)
1T finely chopped fresh oregano (see above about food processor)
1/2C red wine vinegar
1.25C extra virgin olive oil (I never use this much - not sure how much I do use, but it's less)
1/2t finely ground sea salt (I use kosher)
1/4t Fresh ground black pepper
In a food processor, combine all the ingredients and pulse until well-mixed. It makes 2.5 cups but use about 3/4 cup for this recipe - save the rest. It will keep in the fridge for a month.
1T Spanish Paprika (see note above regarding Spanish Paprika)
2T Finely ground sea salt (again, I use kosher)
1C warm water
Combine in a small bowl and stir until salt dissolves.
2 red onions, sliced crosswise (1/2 thick - you want them to stand up to the grill)
olive oil for brushing (not sure if Chris does this or not)
Finely ground sea salt (again)
Freshly ground black pepper
2.5lbs skirt steak about 1/2 inch thick
8 pita breads (we prefer to use flat breads, the pita always seems to fall apart)
1/2 pound blue cheese, crumbled
4 ripe tomatoes, cut crosswise into 1/4 inch thick slices, and those halved (it's winter now, so tonight I'm going to chop up a bunch of grape tomatoes and see how that goes - it worked well)
Get your grill ready for direct heat grilling over hot fire (I believe that means you can keep your hand over the coals for 3 - 4 seconds). Brush onion slices on both sides with oil and season w/ salt and pepper (I didn't season them - there's enough flavor in the sauce). Grill, turning once, until tender and caramelized about 3 - 4 minutes on each side.
Season steaks with salt (didn't do this either since the chili water has so much salt in it) and brush on the chili water. Grill steaks, basting 2 - 3 more times with chili water, turning once, until done (4 - 6 minutes total for medium rare). Let rest 4 minutes.
Now if you're using pita, he has you brush it with oil and grill it, turning once, for a minute. Then he has you cut the top 1/5 off the pita, stuff the pockets with blue cheese and put the pitas in the oven (that's been pre-heated to 225) on baking sheets to keep warm. We don't bother with this. Chris throws our flat breads on the grill for a minute while the steak rests.
So now, you slice the steak, across the grain, into 1/2 inch thick slices and in a bowl, mix it with 1/2C of the chimichurri sauce, tossing well.
Now, divide up the cheese, steak, tomatoes and onions (you know, separate them into rings), among the pitas and drizzle each with the remaining chimichurri sauce and eat.