1400 degree to make the cement part of concrete.
You could may be reach this by solar concentration, but currently we do burn stuff to make concrete.
With meat the important thing is to know the turnaround time, eg. how much time does it take for an animal to reach adult size. Bigger animals tend to have longer lives. More lifetime means more food, water, energy.
Beef has really long turnaround time, pork is not much better, poultry is quite good, insects are really hard to beat. Eggs are also a great source of protein. Having your own chicken coop is not a bad idea, if you have the space for it.
Cement is problematic because the CO2 comes from the process even if you use non-CO2 emitting fuels for heating up the raw materials, which eventually become cement. Alternative to cement is to use wood for construction, which I think is quite popular in the US.