for plain buckwheat (used in sweet recipes), use salt instead of a bouillon cube
If you want to use buckwheat in savory recipes add a bouillon cube to a medium size pot. Let it melt with a little bit of water. You can also add a bit of unsalted vegan butter to the pot for extra flavor and more moist grains.
For neutral buckwheat (used in recipes), add salt to the water instead of bouillon and optionally vegan butter.
Add the rest of the water and buckwheat groats to the pot. Stir, so the buckwheat is emersed in the water.
Cover the pot with a lid and bring to a simmer on medium heat. Let it simmer for about 5 minutes.
When you hear that the water starts to boil, turn the heat down to low. Leave the lid on the pan for another 5 -10 minutes.
Remove the lid to see if all water is absorbed. If there is still water in the pot, let it sit for another 5-10 more minutes with the lid on.
When the buckwheat is done (all water is absorbed, but the buckwheat is still shiny), switch off the heat, leave the lid on the pot and let rest on the hot stove for 5 more minutes or longer if you can. This will remove any remaining liquid without having to cook it further.
Fluff with a fork and serve.