To firm the meat, place it in the freezer for 20 minutes before slicing. While the meat is in the freezer, add the chili powder, cumin, coriander, oregano, salt, garlic, scallions, and jalapeños into a large bowl. Remove from the freezer and cut the steak in half lengthwise. Working with one half of the steak at a time, cut the meat against the grain into ¼-inch thick slices. Add the sliced to the bowl and toss to coat. Cover with plastic wrap and refrigerate for up to 20 minutes.
Heat teaspoons of oil in a 12-inch non-stick skillet over high heat until just smoking. Add half of the steak mixture and cook, turning slices once until browned, about 1 minute per side. Transfer the meat to a clean bowl. Repeat with the remaining oil and meat mixture.
Off heat, add the tomato sauce, water, brown sugar, and lime juice, scraping up any browned bits with a wooden spoon. Meanwhile, using a slotted spoon, transfer the browned meat mixture to a cutting board, reserving accumulated juices in the bowl. Chop the steak into rough 1-inch pieces.
Add the reserved meat juices to the skillet and cook, stirring, until reduced by half to form a glaze, about 6-8 minutes over medium heat. Return the steak to the skillet and cook until the meat is glazed and just cooked through.
Divide the steak among the warmed tortillas or serve family style.
I like to serve these tacos with chopped fresh cilantro, diced white onion, crumbled Queso Fresco, and lime wedges. Enjoy!