Something I heard about years ago called "Lockdown."
Most people have a pantry full of food and continue to go to the
store each week because there's "nothing to eat." Lockdown means
eating from the what you already have on hand and not going to the
store to buy additional food except for fresh items needed.
I haven't done it in a while because I don't have much cabinet
space and keep lots on hand. But I used to do this once in a while
and found I saved lots of money.