Start to finish: 1 hour
2-pound porterhouse steak
2 teaspoons salt, divided
2 cloves garlic, quartered
1 cup fresh cilantro leaves
1 cup fresh mint leaves
1 cup parsley leaves
1/2 teaspoon cayenne
1/2 cup extra-virgin olive oil, plus extra for rubbing the steak
1 avocado, peeled, halved and pitted
Squeeze of lime juice
1 to 2 tablespoons peanut oil (if pan-frying)
Rub the steak with 1 teaspoon of salt, then set it on a plate and let it come to room temperature.
Meanwhile, prepare the chimichurri. In a food processor, combine the garlic, cilantro, mint, parsley, remaining salt, and cayenne. Puree until chunky smooth.
With the processor running, slowly drizzle in 1/2 cup of olive oil. Puree until smooth. Transfer the chimichurri to a bowl and set aside.
Cut each avocado half into small cubes and place in a small bowl. Drizzle with lime juice and toss to coat. Set aside.
Just before cooking, rub the steak with a bit of olive oil.
If grilling, preheat the grill to about 450 F.
Place the steak on the hottest part of the grill and sear for 3 to 5 minutes per side. Reduce the heat on one side of the grill and move the steak there. Cook for an additional 8 to 12 minutes, flipping the steak after about 4 to 5 minutes.
To pan-fry, heat the peanut oil in a heavy pan until almost smoking. Sear the steak for 3 minutes on each side before reducing the heat. Cook for an additional 8 to 12 minutes over moderate heat, turning it every few minutes.
When pan-frying steaks more than 2 inches thick, you may want to finish cooking it by putting it, oven-safe pan and all, in a 400 F oven. This will allow the interior to cook without burning the exterior.
However you cook the steak, aim for about 120 F to 130 F on an instant read thermometer for rare to medium-rare. Season with salt and pepper, transfer to an oven-safe plate, tent with foil and let rest in a warm oven 5 minutes.
To serve, pour a pool of the chimichurri sauce onto each plate or use one large platter. Slice the steak and arrange it on each plate. Top with a neat pile of diced avocado. Recipe adapted from Cree LeFavour's "The New Steak," Ten Speed Press, 2008