Although this is "#3 in the Vorkosigan saga," it's really a stand-alone novel featuring the titular Ethan as the protagonist. Ethan is a medical doctor born & raised on Athos, a gender-separatist colony planet inhabited solely by men. The planet's out-of-the-way location and reputation as a cultural backwater means it doesn't get much traffic, and the men of Athos are isolated and fearful of the outside world - especially women.
However, Athos is in need of fresh ovarian tissue for their artificial replicators. After a mail-order delivery turns out to be unusable garbage, the colony decides to send Dr. Ethan on a business trip off-planet to personally select the medical supplies needed... a trip on which he will have to personally interact with (shock! horror!) females!
What's fun, of course, is that one of the women in question turns out to be Elli Quinn, and the mild-mannered Ethan is unwittingly drawn into a web of spies, assassins and unethical bioengineers.
A well-plotted, entertaining adventure, but I did find some of the bits about the whole men-only society to be a bit cliched... Still, enjoyed both the humor and the action.