To Trim the Outside Skirt Steak (optional)

1. Pat the outside skirt steak dry with paper towels, then trim off any thick or loose pieces of fat. Don’t overdo it, just clean it up a bit.
2. Flip the steak to the other side and run your fingers along the surface; you may notice a thin, silvery membrane (see notes). If you find it, grab an edge with a paper towel and peel it away. It usually comes off in big pieces. If you can’t find it, don’t worry about it and move on. Remember, skirt steak is a thin cut, so it’s better to undertrim than overtrim.

To Dry-Brine the Skirt Steak

1. If you have a whole skirt steak muscle, cut it into a few smaller pieces, about 4 to 8 inches (10–20 cm) long, and ensure they’re even in thickness (see notes).
2. Season both sides generously with kosher salt, then place the pieces on a wire rack set over a baking sheet.
3. Leave them uncovered in the refrigerator for at least 4 to 6 hours, or ideally overnight. While the steak is resting in the refrigerator, make the salsa roja so it’s ready to go when you start cooking.

To Make the Salsa Roja

1. Wash all the ingredients first. Cut the tomatoes in half, quarter the onion, and peel the garlic cloves. Then choose the method you prefer and follow the steps below:

• In a pan: Preheat a 12-inch (30 cm) pan over medium-high heat for about 2 minutes. Add the tomatoes, onion, garlic, and peppers, and cook them for a few minutes, flipping as needed, until they’re nicely blackened. Transfer everything to a food processor and blend until smooth. Taste and add salt if needed.
• In the oven (broiler): Place the tomatoes, onion, garlic, and peppers on a baking sheet and set it just under the broiler. Turn the broiler to high and cook for a few minutes, flipping as needed, until all the ingredients are blackened. Transfer the ingredients to a food processor and blend until smooth. Season with salt to taste, if needed.

To Preheat the Pan

1. Remove the steak from the refrigerator and let it sit at room temperature for about 30 minutes. When you’re ready to cook, place a pan (preferably a cast-iron skillet, carbon steel or heavy-bottomed stainless steel skillet) over medium-high heat and let it heat up for about 3 minutes.
2. Add a bit of high-smoke-point oil and let it heat for another minute. After roughly 4 minutes total, the pan should be hot enough for a good sear, and you’re ready to cook the steak.

To Pan-Sear the Skirt Steak

1. Pat the skirt steak dry again with paper towels, then carefully place it in the pan so the oil doesn’t splash. Cook it based on its thickness:

• For steaks about 1/2 to 1 inch (1.3–2.5 cm) thick: Flip the steak every 30 seconds. Use a meat thermometer to monitor the internal temperature and remove it from the heat when it’s about 10–15°F (5–8°C) below your target doneness (see notes for the temperature chart). Let it rest for about 5 minutes before slicing. Skirt steaks in this thickness usually take 3–6 minutes total to reach medium-rare to medium doneness.
• For thinner cuts (1/4 inch / 1.3 cm or less): Flip the steak every 30 seconds and slide it around the pan every 15 seconds to move it over the hotter spots (this helps build a better crust). Thin pieces are difficult to check with a thermometer, so go by time instead. For medium-rare to medium, cook 60–90 seconds total for a 1/4-inch (0.6 cm) piece, or 2–3 minutes total for a 1/2-inch (1.3 cm) piece. Let the steak rest for 5 minutes before slicing.

To Assemble the Skirt Steak Tacos

1. Once the skirt steak has rested, slice it thinly into strips, then dice those strips into small, bite-sized pieces.
2. Warm the tortillas briefly, flipping them occasionally, until they are pliable. You can do it in a hot pan, in the oven, in the microwave, or right over a gas burner using tongs.
3. Divide the steak between the tortillas, then top with salsa roja, finely chopped onion, chopped cilantro, and a squeeze of lime juice. Serve and enjoy.