The plate: SS/HG is a requirement. My story might be preSS/HG, I suppose.
IF you'll allow that HG having a crush is close enough...
Unexpected visitor: IF you'll allow that SS
in his detested Animagus form is close enough....

Main Course: A Christmas feast.
Veggies: 2. Someone realizes what Christmas is all about. (Well, sorta. Under duress.)
4. A not-so-ordinary sprig of Mistletoe. (Ooops. Poppy's in trouuuuuuuble.)
5. Making angels in the snow. (Ooops. *I'm* in trouble.)
Starch: 4. Someone gets socks. (Minerva from Albus. 'Socks.' Yeah. 'Socks.' )
Gravy: 5. (I'm dreaming of a) White Christmas. (Yes. White and furry.)
Condiments: Someone is the unwitting/unwilling recipient (victim) of a potion.
Puddings! 2. Someone gets an embarrassing gift, opened publicly or privately.
Drinks: 4. "Do I look like a red-nosed reindeer to you?"
5. "Tell me, what do you REALLY want for Christmas?"