You would all hate Xmas dinner at my house. :)
I love mushy peas, not tinned ones, proper "soaky" peas. My lovely FIL makes them for me and tubs them up into individual little portions which I bang in freezer. Dh is cooking and will be putting them on my Xmas dinner dinner Xmas dinner. Dh prefers garden peas but as they are not the "treat" part for him he just has mushy. The pigs in blankets are his treat thing, which nobody else likes but when I'm cooking I'll make them for him.
As for mash, it's the staple of every roast dinner in this house, dh loves it and we have roasties too. Dd likes Turkey whereas dh and I wouldn't bother if it were just us, but we always get a small crown.
Dh is great at making gravy like my nana used to make and it has mushroom in. Yorkshire puddings are an absolute must for all of us too. It might sound like a lot of fuss but it's not our typical Sunday lunch and the extra little bits are things we don't usually have, as there's just three of us it's not that much extra faff. All leftovers are bunged into the pan with left over mash and mixed together for fry up.
id feel differently cooking for large amounts though, on the one occasion I tried it was absolutely impossible to keep everyone happy and almost cost a fortune as I bought three types of peas, steamed and boiled veg, all types of meat, two types of gravy etc etc. Fucking nightmare and never again :)