My all time favorite has been making a trip to Blue Diamond to have their turkey! It is available only on Christmas, New Year's eve and New Years. They have everything from Full Stuffed Turkey, to biriyani and my favorite, the roast turkey (which I eat with cheese sandwich and romali roti)!
Hyatt on Mount Road has a few exensive options! At Spice Market, you have a Christmas lunch for Rs 2399 plus taxes, at Focaccia, the Italian restaurant and Siachu, the Chinese Restaurant, both at Rs 3999 plus taxes.
Benjarong has a special festive menu on from 21st Dec to the 2nd of Jan. Since it is a-la-carte, I am assuming that the prices are on par with the rest of the menu.
I was at French loaf and noticed a huge festive menu. The yule log was super tasty, they have a nice meat loaf puff pastry, nice christmas puddings and a whole lot more. The picture was taken with all the festive foods and there were lots!!!!
Marriott has a special Christmas lunch priced at Rs 1400 plus taxes at the coffee shop and a special 5 course set menu at Rhapsody, if I am right!
Zara's has put up a special Mexican menu between 19th Dec to 6th Jan.
That's all I was able to gather. Wishing you all a merry christmas.