Author Notes

This is a substantial sandwich,tender flank steak that I marinaded in chimichurri and pan seared. I grilled the brioche that's cut extra thick, made a chimichurri mayonnaise, and added slices of fresh tomato. The steak would be equally delicious grilled. - sdebrango —sdebrango

Test Kitchen Notes

This sandwich is a real two-hander -- juicy and garlicky and fragrant. In an inspired move, sdebrango has you make one big batch of chimichurri, which both marinates the steak and also gets swirled in to flavor the quickie aioli. Her steak prep technique -- marinate, then dry brine -- made for one of the best steaks we've had lately, and the resulting sandwich shines because of it (the ripe tomatoes, buttery Texas toast, and aioli help too). Note: In divvying up the chimichurri, we scooped out mostly garlic and herbs to add to the mayo and held back on the oil so it didn't get too runny, and we were very happy. Very. - A&M —The Editors