Staying at Meadowood, dinner at St. Helena and which restaurant?
How much do you want to spend?
One of my FAVORITE places in St Helena that's on the moderate side is Cindy's Backstreet Kitchen - owned and operated by the chef at the famous Mustard's Grill in Yountville - delicious, fresh American food with some Spanish and Mexican influences - my favorite dishes are the roasted quail and the mushroom tamales - I've never been disappointed there.
For something more high-end, Terra or Martini House in St Helena are both excellent. Terra has a bit of an Asian spin, while Martini House offers hearty dishes including fish, game, and meat - they also do a killer mushroom tasting menu.
For lunch, you can't beat Taylor's Refresher, a roadside hamburger stand in St Helena that is so much more than that - my favorite is the Ahi burger, served rare, with sweet potato fries on the side. For a sit down meal, Market in St Helena has comfort food with a local flavor.
I hope this helps - have a great visit in Napa- don't forget to bring a coat! It's been FREEZING here lately! :-)