Cook cous cous according to packaging and when done remove from heat.
Wash mushrooms and then chop into large bite size pieces. Dry saute (do not add oil or liquid) over medium heat until liquids start to release and mushrooms brown and soften - about 8 minutes.
While cous cous and mushrooms are cooking, zest lemon and then squeeze juice into a medium sized serving bowl.
Add shredded parmesan and basil to bowl and mix together gently.
By now your mushrooms and cous cous are done. Allow both to cool a bit before mixing into the bowl - you want to mix while warm but not hot.
Drizzle with truffle oil, and season with salt and pepper to taste.