[Man Against Time]

You are thinking from a 21st century perspective. Ovens? Did people in medieval times have ovens?

...yes.

All we need for bread (or rice or meat) is a plot of land,

"All we need is a plot of land," shows painful ignorance to the complexities of land ownership. Having a system that even allows for it shows an enormous amount of sophistication.

a grinding mill,

Again, implies a complex information network, and more than likely, a system of ownership where a given man or system controls the mill and a given population supplies and rents or uses it. But this is getting away from the point.

and a granary to store the uneaten bread.

Which in your greed as a virtue society, would need a very complex arrangement of security and police forces to prevent the grain from being stolen or sabotaged and poisoned.

In cooking terms, all we need is wood to cook the bread (fire).

No. You do not hold flour over a fire to make bread.

If necessity drives our lives, then we can live like cavemen.

After all, is a computer really necessity to survival? Is a microwave necessary in order to survive? Yes I know today people can't live without mobile phones and computers and cars, but those are luxuries, not necessities.

You are also getting away from the point. This is a stupid modernist trick to arguing, where you make believe everyone has to either endorse living in the mud, or living in an asphalt runaway beast of tens of millions of people.

Guess what- You can have little luxuries and not be greedy. You are leaving out the whole, "No regard for the method of attaining..." aspect of greed. Greed is not, "having more than you need to survive."