In Mexico, the taco is the cultural equivalent of our sandwich--the daily bread with a little something delicious inside. We've used flank steak here since it's readily avaliable, but the author also likes to use cecina, tosajo, or butterflied skirt steak from a Mexican market, or thinly cut round tip (minute, or breakfast, steak) from an American market.
2 1/2 teaspoons vegetable oil or bacon drippings, divided
3 cups (1/4-inch-thick) sliced onion, separated into rings (1 medium)
6 small serrano chiles, quartered lengthwise
3/4 teaspoon salt, divided
1 1/2 tablespoons fresh lime juice
1 (1-pound) flank steak, trimmed and cut into 1/4-inch strips
12 warm corn tortillas
3/4 cup bottled green salsa
How to Make It
Heat 1 teaspoon oil in a large nonstick skillet over medium-high heat. Add onion and chiles; saute 6 minutes. Sprinkle onion mixture with 1/4 teaspoon salt; stir in lime juice. Remove onion mixture from pan. Add 3/4 teaspoon oil to pan. Sprinkle steak with 1/2 teaspoon salt. Place half of steak in a single layer in pan; cook 2 minutes on each side. Repeat procedure with 3/4 teaspoon oil and remaining steak.
Divide steak and onion mixture evenly down center of each tortilla. Top each taco with 1 tablespoon salsa; roll up.