Why It Works
- Broiling the steaks on one side only increases browning and roasted flavor while minimizing the risk of overcooking.
- A baking steel or stone is included as an option for those who want to get browning on both sides of the steaks.
Adapted from Kenji's grilled skirt steak fajitas recipe—with its rich and flavorful lime, soy sauce, and cumin-spiced marinade—this version reworks the technique so that all you need is an oven and a single sheet pan. The best part about making these fajitas on a sheet pan, aside from the quick and easy prep and cleanup, is that it yields a large serving size to feed a crowd, or a very hungry few.
The key is to use the oven's broiler to brown and char the quick-cooking skirt steak. Because home-oven broilers don't offer as much searing heat as a grill can, there's a risk of overcooking the meat while trying to get both sides to brown. To avoid this, we employ what's called "unilateral cooking," searing the steaks under the broiler on only one side to maximize that side's browning potential for a deeply roasted flavor; they're then flipped and cooked very briefly on the other side only for food-safety purposes.
Regular Serious Eats readers know that we always recommend using an instant-read thermometer to judge the doneness of your meat. In the case of skirt steak, though, our experience is the cut is often too thin to get a reliable measurement with a thermometer. For that reason, the recipe does not list doneness temps, but instead aims to maximize browning, which in most cases will coincide with the steaks reaching a good doneness level; if your steaks are underdone, the recipe gives you the chance to finish cooking it at the end after slicing. Still, for anyone who is confident they can temp their skirt steaks properly, here are our recommended temperatures at the center of the thickest part: 115 to 120°F (46 to 49°C) for medium-rare or 125 to 130°F (52 to 54°C) for medium.
This recipe also offers the option of using a preheated baking steel or baking stone, which injects heat up into the sheet pan from below. If you opt for that method, just note that throughout the recipe there are a few small changes to the process (such as no need to flip the steak at all), and you will need to keep an even closer eye to avoid anything burning on the bottom of the sheet pan. Don't be alarmed if your sheet pan buckles when on the hot steel or stone; in our experience, a good aluminum rimmed baking sheet always returns to its normal form on its own.
As with all sheet-pan recipes, it's important to know your oven well and to adjust accordingly. Some broilers are woefully underpowered, in which case you may be better off using only a preheated baking steel or baking stone with the oven at its highest heat setting. Others may be unusually strong, in which case you may need to lower the oven rack just a bit (if you use a baking stone with an oven rack at its highest position, it's possible you won't have the clearance to insert your sheet pan below the broiler element; in that case, lower the oven rack as needed).
- For the Steak Fajita Marinade:
- 1/2 cup (120ml) soy sauce
- 1/2 cup (120ml) fresh lime juice, from 6 to 8 limes
- 1/2 cup (120ml) canola or other neutral oil
- 1/4 cup (55g) packed light brown sugar
- 2 teaspoons ground cumin seed
- 2 teaspoons freshly ground black pepper
- 1 tablespoon chili powder (see note)
- 3 medium cloves garlic, finely minced (about 1 tablespoon)
- 2 pounds (900g) trimmed skirt steak (about 1 whole steak; see note), cut crosswise into 5- to 6-inch pieces ( see our detailed trimming instructions here)
- For the Fajitas:
- 1 large red bell pepper, stemmed, seeded, and cut into 1/2-inch-wide strips
- 1 large yellow bell pepper, stemmed, seeded, and cut into 1/2-inch-wide strips
- 1 large green bell pepper, stemmed, seeded, and cut into 1/2-inch-wide strips
- 1 white or yellow onion, cut into 1/2-inch slices
- 12 to 16 fresh flour or corn tortillas, hot (see note)
- 1 recipe guacamole, for serving, if desired
- 1 recipe pico de gallo, for serving, if desired
- Sour cream, shredded cheese, and salsa, for serving, if desired
For the Fajita Marinade: Combine soy sauce, lime juice, oil, brown sugar, cumin, black pepper, chili powder, and garlic in medium bowl and whisk to combine. Transfer 1/2 cup (120ml) marinade to a separate vessel and set aside.
For the Steak: Place steaks in a gallon-sized zipper-lock bag and add remaining marinade. Seal bag, squeezing out as much air as possible. Massage bag until meat is fully coated in marinade. Lay flat in refrigerator, turning every couple of hours, for at least 3 and up to 10 hours.
For the Fajitas: When ready to cook, preheat broiler and position over rack to highest position. If you have a baking steel or stone, set it
on the top rack and allow to preheat. If using a baking steel/stone, set a rimmed baking sheet on it to preheat as well; otherwise leave the baking sheet at room temperature.
Remove steaks from marinade and blot dry with paper towels. Arrange steaks in an even layer on rimmed baking sheet. Broil, without flipping, until steaks are well charred on top side, about 4 minutes. Broiler strength and oven designs vary greatly, so cooking times will vary as well; keep a close watch. If your broiler heats unevenly, you may need to move the sheet tray around for more even browning. If not using a baking steel or stone, flip steaks and broil for 30 seconds longer (steaks cooked with the help of a baking steel/stone do not need to be flipped and cooked longer). Remove from oven and transfer steaks to a platter to rest.
Switch oven from broil mode to 450°F (230°C). Add red, yellow, and green bell peppers as well as onions to baking sheet. Pour reserved 1/2 cup of marinade all over and toss until evenly coated; using a wooden spoon, scrape up any browned bits on the baking sheet. Arrange peppers and onion in an even layer that covers the baking sheet from edge to edge, then cook, stirring occasionally, until vegetables are tender and browned in spots, about 25 minutes (if your oven heats from the top, you will want to cook the vegetables on a middle rack to avoid excessive scorching and burning). If you're using a baking steel/stone, you can cook the vegetables on it, but keep a closer eye since they run the risk of scorching on the bottom; if this begins to happen, move the sheet pan to another rack.
Slice steak into thin strips across the grain; then add back to sheet pan with any juices. Return to oven to warm through; if steaks need additional cooking, leave them an additional minute or two until they've reached the desired doneness.
Serve immediately with hot tortillas, guacamole, pico de gallo, and other condiments, as desired.
If skirt steak is unavailable, substitute with hanger or sirloin flap (also sold as sirloin tip in New England—it's different from sirloin steak). Flank steak can also be used. For best flavor, grind your own chili powder from a mix of equal parts ancho and guajillo chilies.
You can wrap the tortillas tightly in aluminum foil and pop them in the oven 10 minutes before serving to heat through, while the steak and vegetables are finishing up.
Make-Ahead and Storage
The finished fajitas are best enjoyed immediately.