Carne Asada Tacos

Method

Marinate the steak (2–8 hours ahead)

1. Whisk together everything for the marinade except the steak. Put the steak in a dish or zip-lock bag, pour over the marinade and turn to coat.
2. Cover and refrigerate for at least 2 hours and up to 8. Much longer and the citrus starts to make the meat mushy.

Reverse-sear the steak

1. Take the steak out of the fridge 30 minutes before cooking. Preheat the oven to 120°C (100°C fan / 250°F / gas ½).
2. Lift the steak out of the marinade, scrape off the excess and pat it dry. Lay it on a rack over an oven tray.
3. Roast until the thickest part reaches 46–49°C on a meat thermometer for medium-rare, about 30–45 minutes depending on thickness.
4. Heat a cast-iron pan or grill until smoking hot. Sear the steak for 45–60 seconds a side, just until well browned. Because it's already cooked through, it needs only a quick sear and won't burn.
5. Rest for 5 minutes, then slice thinly across the grain.

Toppings (while the steak is in the oven)

1. Guacamole: mash the avocados with the lime juice, cumin and salt, leaving some texture. No tomato or onion.
2. Queso fresco: crumble the paneer finely with your fingers and mix through the salt.
3. Lime onion: mix the diced onion with the lime juice, salt and a good grind of pepper. Let it sit while you finish everything else.

To serve

1. Heat the tortillas over an open gas flame for a few seconds a side until lightly charred, or in a sandwich press. Wrap them in a tea towel to keep warm.
2. Fill with the steak and top with guacamole, queso fresco and lime onion. Serve with lime wedges.