Couldn't see anything at Waitrose.
I do have Farm shop's near me. Never been to one though. It similar to a butchers?
They'll usually sell meat, fruit, veg, cheeses, jams, chutneys, pickles, pies, cakes, biscuits.
Basically anything you'd associate with the farm whether grown, bred or made. They might not do hampers but it's easy enough to buy a selection and make one up.