3 tablespoons palm or brown sugar, or more to taste
3 tbsp fish sauce, or more to taste
2 to 3 tablespoons fresh lime juice, or more to taste
1 lb skirt steak (or two 1-inch thick hanger steaks (about 7 ounces each))
Kosher salt and freshly ground black pepper
about 1 tbsp neutral oil, such as grapeseed or canola
2 tbsp Shaoxing wine or dry sherry, or more to taste
4 garlic cloves, thinly sliced
1 1/2 inches fresh ginger, peeled and thinly sliced
4 fresh serrano chiles, thinly sliced
1-2 jalapeno, seeded and thinly sliced
1 small red onion, halved lengthwise and thinly sliced
1/2 cup fresh Thai basil leaves
1/2 cup fresh cilantro leaves
In a small bowl, stir together the palm sugar, fish sauce, and lime juice. Taste the mixture. Do you want it sweeter, saltier, or more acidic? It's up to you.
Generously season the steaks with salt and pepper. Heat a cast-iron skillet or sauté pan over medium-high heat until it's smoking. Add just enough oil to coat the bottom of the pan and add the steaks. Cook until beautifully brown on one side, about 2 minutes (or 6 minutes for the hanger steaks), then flip and cook for 1 more minute (or 4 minutes for the hanger steaks) for medium-rare. Transfer the steaks to a cutting board and let them rest for 5 minutes.
Reduce the heat to medium and add the Shaoxing wine, scrape up any brown bits with a wooden spoon. Add the garlic, ginger, and chiles, and cook for 30 seconds, remove the skillet from the heat.
Slice the steaks against the grain. Add sliced steak and all juices to the skillet with the garlic-ginger-chili mixture. Stir to combine. Transfer steak to a mixing bowl and add 2-3 tbsp of the fish-sauce-lime dressing, the onion, and the herbs. Toss. Add more dressing as necessary.