Found this:
http://bbq.about.com/cs/beef/a/aa122803a.htm
scroll down to bottom for recipe (says to serve w/salsa and guacomole so you would need to ensure these were core?) Otherwise recipe looks pretty core friendly except for the orange juice? (and of course you would need to count the tortillas if you were using them).
Here's a couple more:
http://www.koolpages.com/hokuspokus/CarneAsada.html ...and one more which is very core:
http://beef.allrecipes.com/az/CrnsdTcs.asp
Frouf