I did this for a while when I was on apprenticeship wages. Walk past a shop on my way home from work and get some combination of root veg. Ideally what ever they had reduced. Sometimes got bread or reduced meat too.

Then when I got home, stew is ready to eat so put some into a bowl and eat that. After eating, chop up what ever I bought and straight into the slow cooker. Or in the case of bread have that with the stew when serving. Doesn't matter if its a bit stale the next day because the stew softens it up.