We manage on £50-80 a week (family of 4) and the kids eat like gannets.
There are a few dairy/gluten intolerances between us so budget covers things like brown rice pasta, wholegrain rice, coconut milk, which adds to the cost a bit more.
Batch cooking is great but things like lasagna is expensive to buy in one go - the meat alone isn't cheap. You could always replace the meat with lentils (it is actually nicer IMO). Avoid tinned veg as more expensive but things like tomato soup or chicken soup can be a good base for a dish, on a budget.
The only meat we really eat is chicken (get whole and cook it - cheaper) we buy one and spread it to last 3 meals between us, plus using bones to make stock and adding a cup or two of boiling water 10 minutes before chicken is cooked you can use those juices for more stock, plus once refrigerated I use the fat to fry etc. One thing I found with chicken is actually better to buy a ~£5 than the 3 for £10 offers you often find - you actually end up with more meat and it tastes better.
Fruit can be reasonably expensive but depends what you buy - seasonal is the key. Apples and pears are dirt cheap at the moment.
Three tips I would give:
1) Shop around - my local equivalent to Aldi is actually much more expensive on fresh fruit and veg than Waitrose.
2) A good rule of thumb when it comes to fresh fruit/veg - eat seasonal as it is often much cheaper!
3) For some dishes, there is no escaping the need for quality, more pricey ingredients but easy to find ways to make it stretch further.
I shop almost exclusively at Waitrose and still manage that budget - we have limited supermarket choice here (no Aldi, Lidl, Tesco, Morrisons, Sainsbury).
