When on the large chainring (front) does the noise occur consistently through the full range of gears on the rear?

if it tends to make more noise when in the the lower rear gears, or the higher rear gears and quieter in the middle gears then it's probably a front dr adjustment. Look up the "trim" feature of your groupset. you may be just a flick of the lever away from curing the noise.

If its in all the gears, and the noise is truly coming from the rear, it could be that the rear dr is adjusted wrong. look at the dr from the rear and see how well it is aligned with rear cogs. turning the barrel adjuster slightly oneway or the other may bring it into alignment. If this is the problem, you most likely are also having consistently less than perfect shift performance either one way orthe other (meaning it shifts up well, but not down, or vice versa.)

Or go to the LBS.