Slice into wedges yellow onion, red, yellow, and green bell peppers and place in a gallon ziplock bag. Mash into paste one (or two if you like it hot)
chipotle pepper and add to veggies, including "about" one teaspoon of the adobo sauce (careful, it's hot stuff). Mix all together inside bag and let sit for at least one hour.
Also in a gallon ziplock, place flank steak and cover with
LAWRY'S® Baja Chipotle Marinade (not hot but great flavor) and let come to room temp. Save some of the marinade for use in fajita burritos. Marinade for at least one hour.
Flank steak should be grilled on a very hot grill, taking care not to overcook. Before grilling steak, rinse off marinade and pat dry, otherwise it burns and makes a mess. Cook to desired doneness, maybe four minutes per side at the most. It should still be pink inside for best results. Rest steak before slicing.
I use a cast iron wok to cook the veggies right on the grill. Get wok very hot and toss them in, still occasionally until done. Don't let them get mushy!
By the time the veggies are done, the steak is well rested and ready for slicing. Go against the grain and as thin as you can. Wrap up in flour torts, add a bit of the unused marinade, and include a whole chipotle or two if you're brave.
I like 'em hot, but my wife likes 'em a bit milder, so we adjust the spice level as required by using the chipotle peppers. If you don't like spicy, skip the whole chipotle peppers (especially the adobo sauce), but try the marinade - it has no heat and really makes the dish.