I'm not cooking it, but as I understand it, it's not thermidor without some kind of bechamel.
My father in law has been staying with us over Christmas and he goes back on Monday. We plan to take him out for dinner on Saturday and over the break he mentioned that he's not had a nice lobster thermidor in ages. So I called the restaurant and asked if they could oblige - they said yes.
Bubbly isn't a bad idea. I was planning on taking a bottle anyway as an aperitif.
Sorry Wine Expert - I don't have any first growths. I've got a 1996 Penfolds Grange, but I'm sure you'd agree that's probably over the hill by now.