http://www.extremeadventurefood.co.uk
They supply a range of dried foods just add boiling water to a fill line within the bag wait for eight minutes and away you go. The silver bags they come in are sealed and you need to pull a tear strip to open the bag. In its sealed condition they do seem to survive submersion down to 10M.Taste wise there are Ok better than a lot and after all it is a source of energy on long trips or digging trips or beyond sumps or a meal at the caving club when you just cannot be bothered to cook. My favourite is the vegetarian Sheppard’s pie. Heating the water will of course need a source of heat so a small gas burner or you could try a Trekmate chemical heat set.
Andrew
Note:I have no interest in the company and have never had a freebie.