Nutrition per serving may change if servings are adjusted.
½ small red onion, thinly sliced
¾ cup red-wine vinegar
2 teaspoons salt-free southwest chipotle seasoning, such as Mrs. Dash®
½ teaspoon kosher salt
8 ounces flank steak
¼ cup nonfat plain Greek yogurt
1-2 teaspoons lime juice
1 cup torn romaine lettuce
4 tostada shells
1 cup cherry tomatoes, halved or quartered
¼ cup chopped fresh cilantro
1 small jalapeño pepper, thinly sliced
Preheat a gas or charcoal grill to medium.
Combine onion and vinegar in a small bowl. Let stand until ready to serve.
Combine Southwest seasoning and salt in another small bowl. Rub the mixture all over steak with your fingers.
Oil the grill rack (see Tip). Place the steak on the rack directly over the heat; cover and grill, turning once, until desired doneness (145°F for medium), 13 to 16 minutes. Transfer to a cutting board and cover loosely with foil; let stand for 10 minutes.
Meanwhile, stir yogurt and lime juice in a small bowl.
Thinly slice the steak across the grain. Drain the onion; discard the vinegar, or reserve for another use (see Tip). Divide lettuce among tostada shells. Top with the steak, tomatoes, the pickled onion, cilantro and jalapeño. Drizzle with the yogurt mixture. Serve with lime wedges.
Tips: To oil a grill rack, oil a folded paper towel, hold it with tongs, and rub it over the rack. (Do not use cooking spray on a hot grill.)
You can use the reserved vinegar from the pickled onions to make salad dressing or in any other recipe that calls for red wine vinegar.