Not the most exciting present, but how about a John Lewis gift card, then they can either buy something for the home that they need or can buy food in Waitrose?
I always make up a hamper for my oldest son with lots of more expensive little foody treats that will keep, nothing fresh except perhaps for a small salami/chorizo or chunk of parmesan. I include things like a bottle of a more expensive olive oil, balsamic vinegar, unusual pasta, pesto, tinned anchovies, spices and so on.
My DD is very hard up and I sometimes do her an online grocery shop as a treat, buying her usual day-to-day items but also some tinned or bottled treats.
I used to buy my mother half bottles of wine as she didn't like to open a whole bottle just for herself.