1 teaspoon ground cumin
1/2 teaspoon ground coriander
coarse salt and ground pepper
1 pound skirt steak, cut crosswise into 2 equal pieces (if too large for skillet, cut into smaller pieces)
2 red bell peppers (ribs and seeds removed), halved and thinly sliced
1 red onion, halved and thinly sliced
1 to 2 jalapeno chiles (ribs and seeds removed), very thinly sliced lengthwise
2 tablespoons fresh lime juice
8 flour tortillas (6-inch)
sour cream and lime wedges, for serving
In a small bowl, combine cumin, coriander, 2 teaspoons coarse salt, and 1/2 teaspoon pepper. Rub steaks all over with spice mixture.
Heat a large skillet over medium-high; add meat (if crowded, cook in two batches). Cook 2 to 4 minutes per side for medium-rare. Transfer to a cutting board. Tent steaks with aluminum foil, and let rest at least 5 minutes.
Meanwhile, reduce heat to medium; add bell peppers, onion, and chiles; season with salt and pepper. Cook, stirring occasionally, until crisp-tender, 8 to 10 minutes. Add lime juice, and stir, scraping up browned bits in skillet.
Stack tortillas, and wrap in a damp paper towel or kitchen towel. Microwave on high 1 minute. Thinly slice steaks crosswise, and serve with tortillas, peppers, onion, and chiles, along with sour cream and lime wedges.