tea and wholemeal/multigrain bread from the UK (it would not be the case now since I make my own bread). Maybe also baking powder. Where in France do you live? In Paris who have all the spices you can think of, and cheaper than in London, although in other areas it might not be the case.
I am not British, and do not like cheddar. Even in London I only eat Italian or French cheeses.
Now the list of things I miss from France and Italy would be a bit long to publish....
You do get most of them here, but they cost a fortune. Fruit and vegetables are particularly bad in London, where I live.