For cumin marinade, place ingredients in a small bowl, stir to combine and set aside.
Place beef in a non-reactive container, add cumin marinade, turn to coat and refrigerate for flavours to develop (4-6 hours).
For chipotle-tomato sauce, heat oil in a saucepan over medium heat, add onion and garlic and stir occasionally until tender (3-4 minutes). Add tomato and chillies, and simmer until slightly thickened (5-6 minutes). Transfer to a food processor, blend until smooth, return to saucepan and cook over medium heat until reduced to a sauce consistency (7-8 minutes). Season to taste and keep warm.
For guacamole, coarsely crush avocado in a bowl, add tomato, onion, coriander and chilli, stir to combine, add lime juice and season to taste, then set aside.
Heat a char-grill pan over medium-high heat. Drain beef from marinade and char-grill, turning once, until cooked to your liking (1-2 minutes for medium-rare). Set aside to rest for 5 minutes then cut into 1cm-thick slices.
Warm tortillas in a large frying pan, spread with chipotle-tomato sauce, top with guacamole, sirloin and coriander and serve.
Note Andrew Blake prefers to use Hopkins River beef. Chipotle
chillies in adobo are available in cans from select
This recipe is from the April 2013 issue of Australian Gourmet