The way we ate in Cardiff was fabulous. Three of us stocked up in Lidl every 2 or 3 weeks, and just lived off that food, averaging a spend of about £10 a week each on food.
A typical meal would be pasta (25p), red pesto (55p), tinned mackerel (29p), chopped onion/spring onion/shallots (20p) and chopped peppers (30p). That's 53p each and delicious. Takes hardly any time, produces little washing up and is generally fabulous.
That's what you can do with proper kitchen facilities and a properly cheap supermarket. That's why I started this thread.