I think I'm going to do a tuna casserole, it's not one of my favourites, but N has been asking for one for ages - and more importantly, we have all the ingredients available (including garlic bread to accompany it in the freezer) and our grocery delivery isn't due until tomorrow.
So it would seem the sensible option.
I do actually have most of a roast chicken leg in the fridge (Jakey's one that I cooked last night, he only managed a little bit of it but that little bit did seem to make him happy in his final hours which is great) so I might do a chicken version (think "chicken supreme" retro style thing) for myself to use that up - although it's a bit sad that he couldn't manage more than the little bit of meat I chopped up for him, there's no point in wasting what's left.