While in California, I made guava paste with my mom. We had never made it before (never made anything with guavas, actually), but we had guavas and didn't want to waste their wonderful scent!
I googled a recipe, but the basic idea is to cook the guavas, strain out the seeds and thick fibers, measure the puree and add an equal amount of sugar, then cook the mixture until thick (about 4 hours!). I actually had to leave for my plane home before it finished cooking, so my mom finished boiling the guava paste and mailed me a big chunk.
This is delicious - I love how it turned out and will certainly make it again. We have been enjoying it with slices of salty cheese.