Let me see... well, a delicate chai tea will pair nicely with the chocolate cake, there's a light spice to it that contrasts the richness of the chocolate. Chai can work nicely as well.

For the lemon cake, a camomile will compliment the flavours nicely. It's a rather calming tea, in my experience.

[She'd be more than happy to gone on about this for a while, given the chance, but was conscious of giving him too much information at once.]

That would be a good starting point.