1 1/2 lb flank steak, trimmed if necessary
2 1/2 Tbsp Fajita Seasoning
1/2 teaspoons salt
1 heart of romaine
2 firm-ripe avocados (8 to 10 oz each)
12 (6-inch) flour tortillas (not low-fat)
1 cup loosely packed fresh cilantro sprigs
Accompaniments: tomatillo salsa; lime wedges
Heat a well-seasoned ridged grill pan (preferably cast-iron) over moderately high heat until beginning to smoke, then brush cooking surface with oil.
While pan heats, pat steak dry and stir together Fajita Seasoning Blend and salt, then rub spice mixture all over both sides of steak.
Grill steak, turning over once, 9 to 11 minutes total for medium-rare doneness. Transfer steak to a cutting board and allow to stand 10 minutes.
Meanwhile, cut romaine lettuce crosswise into thin shreds. Quarter avocados lengthwise, then pit, peel, and cut lengthwise into 1/4-inch-thick slices.
While steak is standing, stack tortillas, wrapped completely in dampened paper towels, on a microwave-safe plate and cook in a microwave oven at high power (100 percent) until tortillas are hot, about 1 1/2 minutes. (Alternatively, take 4-5 tortillas, roll together in aluminum foil, and heat in oven at 170 – 200F for several minutes to warm and soften).
Holding knife at a 45-degree angle, thinly slice cooked steak across the grain. Serve with tortillas, avocado, romaine, and cilantro.