I like where your imagination is taking you
Except 1 thing: B777's don't crash unless you make it crash
But to continue with your story, you'll have to decide how damaged it is (and what caused it), do you still have battery power (for a short time anyway)?
If so, you'll have radio.
BTW they say the battery lasts about 30mins on a flying/systems powered plane.
Coffee makers have a boiler of about 1ltr, depending on aircraft configuration there are about 10-14 on board. They run on electricity (unless you want to boil the water on a campfire
)
Good luck