To learn more, read the article: In a medium skillet, heat 1 Tbs. of the oil over medium heat. Add the onion, garlic, jalapeño, and 1/4 tsp. salt. Cook, stirring occasionally, until softened, about 3 min. Transfer to a medium bowl, let cool for 10 min., and then add the ground beef, cumin, oregano, cilantro, 1 tsp. salt, and several grinds of pepper. Mix gently with your hands until just combined. Shape the meat into four burgers, 3/4 inch thick and 4 inches across, working the meat as little as possible. Make a 1/4-inch dent in the center of each burger with the tips of your middle three fingers. To pan-cook burgers: Put a large skillet or griddle, preferably cast iron, over high heat and let it get very hot, about 2 min. (The pan is hot enough when a drop of water evaporates instantly.) Add the remaining 1 Tbs. oil and tilt the pan to spread it evenly. Arrange the burgers so there’s as much space as possible between them, reduce the heat to medium high, and cook, uncovered, for 5 min. Turn and cook until the burger feels springy but not mushy when poked, about 3 min. for medium rare (or longer if you’re concerned about undercooked meat). To grill burgers: Charcoal: Prepare a medium-hot fire. Cook the burgers, uncovered, on one side for 5 minutes. Turn and cook until the burgers feel springy but not mushy when poked, another 4 to 5 minutes for medium rare. Gas: Heat the grill to high. When the interior temperature is about 500°F, cook the burgers for 3 minutes with the lid closed. Turn, close the lid, and cook until the burgers feel springy but not mushy when poked, another 3 to 4 minutes for medium rare. To serve: Cut the top inch or so off the pitas to open up the pockets wide enough to fit the burgers. Serve the burgers in the pita with red onion and lettuce, if using, and some of the chimichurri sauce.