Step #7 Add salt, pepper, and, if desired, truffle oil.
Step #8 If too thick, 1/2 tsp at a time, add olive oil (or more truffle oil if you want a stronger flavor), to desired consistency.
Step #9 Place mixture in a pastry bag with a plain or star-shaped tip (or a small zip-top plastic bag with a corner cut out), & pipe mixture into remaining egg halves.