I have been experimenting with buckwheat recipes recently. They have a lot of potential for backpacking meals. Buckwheat is not a grain but cooks up much like rice, but with man advantages. One is it cooks quickly. I bring 1 part buckwheat and 2 parts water to a full boil, turn stove off, let set in cozy for 15 to 20 min. Most rice will not cook this fast. Red lentils and basmati rice cook in the same condition and make a great combination. I add olive oil, meat, salt and seasonings (Madras curry is great). I don't know how it would do with FBC. Perhaps someone could try and report. The cooked buckwheat has much the same consistency as cooked rice so should substitute well in recipes. You will need to experiment to get the taste and consistency you like.
Buckwheat is more nutritious than rice (more fiber, protein, vitamins, minerals). It also has more flavor. As for availability, buckwheat is popular in eastern Europe an central Asia so I get it at our local import food store owned by Bosnians. As it is gluten free, you might find it in the GF section of your grocery store. Otherwise there is online shopping. It is not expensive.