I am infusing olive oil with truffles. How can I do it safely? Heating the oil destroys the truffle smell and pickling it is a sure way to do the same. Are there any other methods? Perhaps some type of filter that will eliminate the particulates? 
In this recipe, the nibs are being used as an accent ingredient, adding some crunchiness and a burst of chocolate flavor, as well as some bitterness.  They are not essential to chemistry or overall outcome of the recipe.  You may:   Simply omit them Chopped or coarsely ground roasted coffee would have a similar profile, although not as fatty, and of course, coffee flavored Try another crunchy, possibly somewhat bitter ingredient like chopped nuts; almonds, hazelnuts, and (in some people's opinions, although I dislike them) walnuts have a particular affinity for chocolate.  