I'm pricing this low because a researcher can probably answer from
personal knowledge.  (I don't require a carefully researched answer,
just an informed opinion.)  Comments are also encouraged.  :)

My boss is Jewish, and I'm Christian.  He's not a person who's looking
for an excuse to get offended (I've known some of those from various
faiths, and they're tricky to deal with), but I'd prefer not to be an
insensitive clod when it comes to holiday gift giving.  Because I'm
broke, I was planning to make some challah bread over the weekend (I
have a recipe that I've been wanting to try) and give it to him on
Monday with an appropriate card, since it will still be Hanukkah then.
 I have given him baked goods before for other occasions, so that
isn't the issue in question.  Here are my questions...

1.  Is there anything wrong with this plan (e.g., challah bread is too
sacred to be made by non-Jewish people, or is never eaten during
Hanukkah)?

2.  Is there a different baked item that would be more appropriate for Hanukkah?

3.  What about packaging?  (I'm guessing not red and green.)

4.  What about a card?  I have Christmas cards, or I could get a
Hanukkah card if that wouldn't be inappropriate.  Or I could get a
generic "Season's Greetings" card, but I don't like those.

You have very good intentions, but let me give you some advice. First,
there is nothing "sacred" about making a Challah.  It is simply a
twisted egg bread that is traditionally eaten on the Sabbath (Friday
sundown to Saturday sundown.) Challah has no real significance to
Chanukah, except that it would be eaten on the Sabbath that happens to
fall during Chanukah.
Chanukah is a celebration of the resiliency of the Jews and is
symbolized by a light burning for 8 days when there was only enough
oil to keep the light burning for 1 day (very condensed explanation.)
Therefore, traditional Chanukah foods are made in oil.  The most
popular dish is latkes which is chopped potatoes fried into pancakes
in oil.  There are many variations on how to make them and they can
include spices or chopped onions as well.  Latkes are often served
with apple sauce or sour cream.  Another traditional food is jelly
doughnuts.
As far as the card goes, anything Christmas like is not appropriate.
Most card stores have a selection of Chanukah cards too.  If none are
availabe, "happy holidays" or "season's greetings" are an okay
alternative.
As far as Chankah starting, last night (Tuesday the 7th) was actually
the first night.  Chanukah is 8 nights long so you still have time.
Good luck

It could be a bad move

If your boss is Kosher, then he cannot eat it.
Cooked by a Goyim in a non-Kosher kitchen with unknown ingredients.

I suspect that the real question is: 'How can I seduce my boss ?'

If you are working in a lab, then it is probably a foregone conclusion.

Determine whether you boss "keeps" kosher (not "is" kosher, which
would imply he is edible by Jews).  If not, you should be safe baking,
else find a kosher bakery in your area (good luck if you're not on the
coast).  Rugelech is another popular Jewish pastry you might consider
(lots more here: http://www.jewish-food.org/recipes/ptrindex.htm or
here http://www.jewish-food.org/recipes/chaindex.htm).

Blue and white (or just blue) packaging would be most appropriate.

(BTW, I am a lapsed Catholic.)

There's a whole page on rugelech.  http://www.jewish-food.org/recipes/rugindex.htm

Thanks for the suggestions, everyone.  I like the idea of rugelech, so
I might do that.  (My boss doesn't eat kosher, so he has eaten things
I've cooked in the past.)

Hello biophysicist-ga,

Today's paper had an article just for you. Enjoy! 

http://www.sfgate.com/cgi-bin/article.cgi?f=/chronicle/archive/2004/12/08/FDG74A59CR1.DTL
At Hanukkah, get ready for frying and more frying

how about something simple like hanukah cookies.  a nice sugar cookie.
 there are inexpensive cutouts/molds which you can use to make hanukah
shapes (dradel, menorah, etc).

Like others have said, I understand your good intentions, but challah
bread isn't really associated with the holiday.

Sorry I dont have any suggestions, but good luck!

Just my 2-cents, but you don't really need to give your boss something
"Jewish" at all, just as a present for Christmas doesn't need to be
overtly Christian.  Some home-baked brownies would be very
well-received, I'm sure.

pafalafa-ga

May I add my 2 cents here?

I've been dating a Jewish man for the past 6 months. I was born in
Germany and was originally Catholic...

My man is NOT of the Kosher variety and even eats pork!!!
I think it all depends on whether the boss is still very into the
religious realm...

BTW: I sent my guy a Christmas card and he loved it!

Steph53

Jelly doughnuts are another Hanukkah speciality.  Just get good ones
with lots of rasperry jelly.  In Israel Jelly doughnits are the
"desert" of Hanukkah!

Jeffrey

Just as a general point, I think it is far better policy for gifts to
go down the chain of command rather than up and I think it is
preferable to discourage giving gifts to superiors.  That said, your
gesture seems very kind and thoughtful.  I'm just speaking in
generalities.