Okay, here's an odd one for you, need to know a little about buying food in London.
Newlyweds leaving USA for London next month, to spend 5 years.
We are digitizing the family cookbook so they will have familiar recipes handy on a disk.
Here's the rub: lots of the recipes call for stuff I don't know if they can get. What are the odds of them being able to get:

Flour tortillas
Salsa
green enchilada sauce
green chilies (can)
Jell-o
marshmallow fluff
Mogen David wine
Beau Monde seasoning