ABOUT SKIRT STEAKS.: Go for the outside skirt. It comes from the diaphragm between the sixth and twelfth ribs. It is thicker, more tender, and more uniform than the inside skirt. You may have to order it from your butcher because most go to restaurants. It may come with a membrane attached that is easy to remove.

1) MAKE THE MARINADE. : Squeeze the oranges and pour 3/4 cup of the juice into a large bowl. Squeeze the limes and add 3 tablespoons of the juice into the bowl. Peel and press or mince the garlic. Finely chop the chipotles and the cilantro and add them along with the cumin, salt, black pepper, and oil. Puree all this in a blender or food processor. It doesn’t have to be perfectly smooth. Measure out 1/4 cup and put in a small bowl in the fridge for use as a sauce. Return the rest to the large bowl.

2) MARINATE THE MEAT. :

Cut the meat with the grain into 6-inch lengths (the white lines in the image above). Put on so2) MARINATE THE MEAT. me gloves, add the meat to the big bowl with the marinade, and massage it in. Let them get to know each other in the fridge for 1 to 3 hours.

3) PREP.: Slice the peppers in half, rip out the stems and seeds, and cut what’s left into 1/4-inch slices. Cut the top off the onion, peel the onion, cut it in half pole to pole, and then slice it into 1/4-inch half-moons. Cut the tomatoes in half and, over the trash, squeeze out the seeds and gel. Chop what is left into 1/4-inch chunks and put them in a bowl. (Don’t cut the avocado yet or it will turn brown.)

4) FIRE UP.: Put the charcoal chimney on top of the cooking grate on your grill. Fill it halfway with briquets and light it.

5) COOK THE FAJITA VEGETABLES. : When the coals are white and flame is shooting out of the top, put the cast-iron skillet on the chimney, add the oil, spread it around, and add the bell peppers and onion. Cook just until they soften a bit, but leave some crunch, about The 4 minutes. If they scorch a bit, that’s OK. Pour them into a bowl.

6) WARM THE TORTILLAS.: With a paper towel wipe the oil from the pan being careful not to burn yourself. Working quickly place one tortilla at a time in the pan and heat them until they toast slightly on one side. Take them out and stack them on a plate and cover with foil to keep them warm.

7) COOK THE MEAT.: Remove the pan and put a wire grate on the chimney. Remove the meat from the marinade, wipe off the excess marinade, put the meat on a plate, and head for the chimney. Grill one chunk at a time. Sear one side quickly, 1 minute is all, and then flip and sear the other side until it has good color and the interior is 125° to 130°F. Move the cooked meat to a cutting board. Cut across grain into 1/4-inch strips as shown by the black lines in the photo. Put them in a bowl.

8) AVOCADO. : Carefully run a knife around the avocado cutting it in half from pole to pole. Twist the halves apart and with a spoon pop out the seed. Cut the halves again so you have 4 quarters. Scoop the meat of the fruit out of the skins, cut it into 1/4-inch slivers, and put them in a bowl.

9) SERVE. : Now set all the bowls on the table, meat, onions and peppers, tomatoes, and avocados—and don’t forget the sauce in the fridge. Let your guests assemble their fajitas as they wish.