In reply to phja:
I have a dehydrator. The cheap ones (like mine) have mesh trays and aren't really suitable for drying liquids so I haven't attempted dried meals yet.
I have had good results doing things like dried apples, peppers, vegetables, tomatoes etc. and either eating them raw or using them as cooking ingredients.
A mix of dried mushrooms, peppers, aubergine and tomatoes along with a few herbs makes a good and easy pasta sauce for example.
I never bother with dried mushrooms, as you can buy good and cheap ones anywhere. One of the books I have strongly advises against onions!