Instant Hummus Pre-cooking without Dehydrating
Raw chickpea flour is unpleasantly bitter, but it becomes delicious when dry roasted or fried in a little oil.
It takes some practice to achieve exactly the right degree of roastedness. You will notice while dry roasting that the flour starts to become aromatic, and then smells slightly over-roasted and rather suddenly turns light brown. I recommend roasting it until just before the colour change for this purpose. Stir constantly and break up lumps to roast evenly.
This pre-roasted flour will not need further cooking. To reconstitute you simply add a little water, mix, add more water, mix, and keep going until the consistency is what you want. You can immediately eat it, you can use cold water for this, and you do not need to cook it.
You can also lightly dry roast and grind sesame seeds, probably along with the chickpea flour. Avoid grinding sesame seeds alone too finely, as they will turn into tahini.
Presumably you have access to garlic powder.
A dry substitute for lemon juice could be sumac (a type of berry which is dried and powdered), as suggested by Chris H.