This looks to me like a female/immature White-tailed Robin - congratulations!
White-tailed Robin is one of the species which has generally been considered an escape, but a female bird in December just after a cold front must have as good a chance of any of being accepted as a wild bird.
Cheers
Mike K
							
							
							
													 
													
								Mike KilburnVice Chairman, HKBWSChairman, Conservation Committee