They're such a weird little pairing, but the stuff that really gets me is when writers lean into the emotional tension that's already baked into their canon dynamic. Chilchuck's pragmatic cynism grinding against Laios's naive enthusiasm creates this amazing friction. I've found that most of the good, angsty stuff for them lives on Archive of Our Own, but you've gotta use specific tags. Search 'Chilchuck/Laios', obviously, but also 'emotional hurt/comfort', 'pining', and 'mutual pining'. Sometimes 'unresolved tension' yields good results.
I read one a few months back that was a masterclass in stretched-thin nerves—set after a dungeon crawl where Laios gets injured and Chilchuck is just vibrating with repressed worry and frustration. The writer spent paragraphs on Chilchuck noticing the way Laios's hands shook, but refusing to say anything. It's that specificity of observation that sells the tension. Tumblr blogs dedicated to 'Dungeon Meshi' sometimes link to shorter, more intense pieces that don't always get cross-posted, so that's another avenue. The real meaty explorations of their emotional landscape, though, tend to be longer one-shots or slow-burn multi-chapters on AO3, often filtered under the 'Chilchuck Needs a Hug' tag, which honestly, he does.