Soda bread is probably the quickest and easiest one to make. Under an hour and it's ready to eat.
Any flour, a little salt, a little oil or fat if you have some, and some baking powder.
If you use bicarbonate of soda (more stable long term than the BP mix then you need an acid of some kind to kick start it. Some folks use buttermilk (added value) but you can just use tartaric acid, which again lasts for ever )
Thing is though; there's bread and then there's 'bread'.
It worth playing around with though.
We're used to yeasted breads here, oat and rye are dense, still nutritious but heavier than most would prefer.
Personally I think it's worth the time and effort to get the yeast working, but soda bread's pretty good