Which off the shelf foods last the longest?

[Skvez]

Protein

Tins are expensive but usually have a 1 or 2 year (marked) shelf life
Tesco (and other main supermarkets) have a reasonable range of Tined Chicked, tinned Tuna etc

Carbohydrate

I find that potatoes don't store well for as long as a year unless you have a root cellar (I wish)
Tinned potatoes do sreo.
Rice and pasta can usually be found in packages that are stated "best before > 1 year from now". Often it's the slightly more expensive brands with the longer shelf life. Not sure if that's in the preparation or the packaging itself.
Bread: I don't yet have a good long term way to provide bread. I store a little flour but I don't bake bread with it, more bannack type substances.

Fruit / vegetables

This is an area that I'm lacking in.
Tined vegetables tend to taste poorly and often don't have as long as a year date.
Ideally I can get a small vegetable garden going, ideally in a greenhouse so I can continue to produce during the winter (someday).

Milk

Long life milk (UHT) is usually only out about 6 months, it's also more expensive than fresh so I only have a few litres on hand (not nearly enough). Powered milk after that.

Butter / Margarine
No long term preps at this time. (I need advice here!)

So a lot of tins which is a shame as tins are expensive, heavy (if I needed to bug out) and rust (if I try and cache them). There are also some people who express health concerns using a lot of tinned food and we need to rotate what we prep.