To save money i do a BIG shop once every 6 weeks and batch cook LOADS.
Il spend £50 on several large packs mince, chicken ect.
Carrots, bag of peas, curry sauce, barbeque sauce, tinned tomatoes,pasta.
I make cottage pies, lasagne, chili, spag bol. With the chicken i do hunters chicken, curry and some mini roasts (2x chicken breast,stufing ball, sausage in a foil tray ready to roast) i will also pre make roast potatoes and freeze in portions and portion up the wedges for the hunters chicken. I bought loads of takeout tubs from the £1 shop but wash and reuse them each time.
its only 2 adults and a 2yr old though so not exactly a family of 4.
Not only does this saves money on the actual meals themselves... and also means its almost NEVER that i would need to nip to the shop for a top up. Other than say a load of bread or milk.
I used to shop lidl but never saved me any money as oftrn have to buy vegies in larger packs than i would need. So i swopped to the free click and collect at ASDA. This saved me even more-money and time. I cant remember thr last time i had to do a physical food shop. I probably spend £30-40 a week and includes fresh fruit ( veggies are frozen bags)
Online shopping means i plan meals better and dont add in yummy ££ extras!