One company I used to work for went through a saga of finding the best compostable material for disposable cutlery. I think the first attempt was some black plastic thing that melted if you used it to cut an orange. Next was pressed bamboo, which worked but it tasted like wood. Next was a starch based thing that would melt in a cup of tea. I think they finally ended up with some kind of hard brown plastic, but by that time I just had a titanium spork from REI.
So the answer is just bring your own fork and rinse it off when you're done.