Tynan,
I highly recommend taking your grandparents to Grassfield's Food and Spirits up in Andover (or Waltham). Good fare for good prices, plus you'll feel as if you stepped onto a set of extras for Golden Girls. There may not be any Amys there, and it's probably not the most vegan-friendly place in the world, but as my atheist friend puts it, the chicken teriyaki with rice pilaf is the closest he'll ever come to a religious experience.
BB