Aaron Hernandez -- Even Accused Murderers Deserve Turkey

Aaron Hernandez -- the ex-New England Patriots star who is behind bars as he awaits trial for murder -- will be celebrating Thanksgiving with SOME of the trimmings ... TMZ has learned.

Here's what we're told Aaron will be eating:

-- 5 ounces of turkey
-- mashed potatoes
-- mixed veggies
-- fruit punch

We're told the reason the inmates get turkey dinner is to remind them there's still a lot to be thankful for.

And the pièce de résistance ... for desert he gets one slice of pumpkin bread.

And you know what he has to do to get 2 slices ....