If you like your beef more rare, keep the steak whole and rub with seasonings; grill about 3 minutes on each side. Let steak stand 5 minutes; cut across grain into thin slices. If you'd like something richer than sour cream, try crema Mexicana, usually located with the Mexican cheeses. Keep the vent hood on as you cook the steak; the chile powder can be quite pungent.
2 tablespoons canola oil, divided
1 tablespoon fresh lime juice
1 teaspoon brown sugar
1 1/2 teaspoons chipotle chile powder
2 large garlic cloves, minced and divided
1 (1-pound) skirt steak, trimmed and chopped
1/2 medium onion, cut into 1/2-inch-thick slices
1/2 pound plum tomatoes, halved lengthwise
1 red bell pepper, halved and seeded
5/8 teaspoon salt, divided
1/4 teaspoon dried oregano
1/4 teaspoon freshly ground black pepper
8 (6-inch) corn tortillas
1/4 cup reduced-fat sour cream
How to Make It
Combine 1 tablespoon canola oil, lime juice, brown sugar, chile powder, and 1 minced garlic clove in a large zip-top plastic bag. Add steak; seal and toss to coat. Marinate at room temperature 30 minutes.
Heat a large grill pan over medium-high heat. Brush the remaining 1 tablespoon canola oil over onion slices, tomatoes, and bell pepper. Arrange the vegetables in pan; cook for 4 minutes on each side or until charred and softened.
Combine tomato, 1/4 teaspoon salt, and remaining garlic clove in a food processor or mini chopper; pulse until almost pureed. Place tomato mixture in a medium bowl. Coarsely chop onion and bell pepper; add to bowl. Stir in oregano and black pepper.
Heat a large cast-iron skillet over high heat. Coat pan with cooking spray. Add steak mixture to pan; cook for 6 minutes or until done, stirring frequently. Stir in remaining 3/8 teaspoon salt.
Heat tortillas according to the package directions. Arrange about 1 1/2 ounces steak on each tortilla; top each tortilla with about 2 tablespoons salsa and 1 1/2 teaspoons sour cream.