Buckwheat

Despite the name, buckwheat is not wheat at all but a seed from a flowering plant, which makes it naturally gluten-free and a staple across Eastern Europe, Korea, Japan and the Himalayas. It cooks quickly — about 12 to 15 minutes — and behaves on a knife-edge: undercooked it's chalky and brittle, overcooked it slumps into mush. The trick is the same as for rice: rinse first to wash off bitter dust, then toast briefly in a dry pan to bring out a nutty flavour, before adding boiling salted water at a 1:2 ratio and lidding tightly. Drain promptly and let it steam off the heat.