Marinating the steak before cooking in a simple mixture of oil, lime juice, and herbs takes these delicious little tacos to the next level. We smear the tortillas with guacamole before topping with the steak, onion, and cilantro, but you can add other toppings, too. Try shredded lettuce, low-carb salsa, sour cream or chopped radishes. This content is only available to members.