I remember when I was a student eating lots of rice dishes (simply frying the rice in some oil before adding a stock cube and any veggies / meat that I had hanging around), and using beans and pulses - bean stew was a favourite. Some fish, such as mackerel, is very cheap.
Shopping cheaply makes all the difference. If you go to East St market towards the end of the day you should be able to find produce being sold off cheaply.
is/was the Delia book called Frugal Food? We used to have a copy as well but ours has also disappeared! I'm sure I saw a copy on one of the second hand bookstalls down by the NFT,if I see it again I will grab a copy and pm you,there is another good book called the Paupers Cook Book,if you google it I am sure it will pop up. I'll look out for that as well (I am barred from buying any more books for home prior to our move)
I just bought some Greens from Sainsbury's for 50p. Stir fry (quick at high heat) half of it (25p) for dinner with ginger, crushed garlic, and a table spoon of rice wine. Add a little fried shallots - optional(£1 per container with about 20 serving) and served with a little bowl of steam rice. Guess it's less than a pound altogether? Fresh, healthy and yummy. My friend used to swear that her kids would not touch vegetables until I cooked them this dish.
Cooking gadgets - a large wok or pan with a bamboo spatula for the stir fry, and a rice cooker for the steam rice. Nothing fancy. It all took about 15 mins to wash, slice and cook.