"Great basic recipe with no exotic, hard-to-find or expensive ingredients, except the sirloin! For those with budget concerns, a tri-tip, flank or other lean cut will work as well.
To control the hotness, take special care with the jalapeños: halve lengthwise, and with a very sharp paring knife cut out every vestige of white membrane, and for further tempering, the lighter green flesh just beneath them. By taking this extra step you can increase the number of peppers for more robust flavor without making the salsa too fiery to the average palate.