Buying frozen fruit,berries etc,is way cheaperbythan buying them fresh,i even buy frozen in summer. As i live alone i buy frozen veg too,saves it going off and being thrown away. I buy chicken family size pieces,not fillets,i get 3/4 meals out of that.Turkey steaks are cheap,marinated they can be delicious.Get those at Lidl.I buy long life milk,lasts ages,buy packets of nuts,seeds oats etc,in Lidl ,make my own museili,add a banana and easy peeler.
Even in M&S if you go in evenings they reduce stuff well.i got their large calamari pack half price last week,great in pasta,i use dried wholemeal,and making own sauces way cheaper than bought ones. And tinned sardines and mackeral i do prefer M&S in olive oil,you can grill them like fresh ones or use them in pasta,tinned anchovies too Aldis and Lidls are fine.
I used to spend far too much on food,but ive definitey saved money recently.