From a democratic point of view the only thing that makes sense to me now is a snap election. The Tories have now had one PM resign in disgrace and then seemingly failed to set up an acceptable new cabinet. I see no reason why they should keep their mandate without renewed voter support. I suppose the king could instruct Labour to try to form a minority cabinet, but that's beyond my understanding of the procedures of…
By what process do you think there would be one? Unless the Conservatives decide that they don't want to be in power any more, there is no way to make an election happen.
To give an extreme answer: a general strike.[0]
The government has already shown that it will remove senior ministers in response to market turmoil, so this sets the precedent that something like a general strike (which would be hugely damaging to the economy) could be enough to remove Truss.
In the short term that might only lead to a new "caretaker" PM who will attempt to run things for the next couple of years, but it might also embolden those who organised the general strike to try again, and again, until an election was called.
[0] https://metro.co.uk/2022/10/09/what-is-a-general-strike-as-u...