Rinse the grains well.
Put the grains in a pot. Add the water and salt. Place a cover on top of the pot.
Bring water to a boil and then lower heat to a simmer.
When no water is left (18-20 mins), turn off the heat, add the butter on top, and cover the pot with a lid again.
When the butter is melted, fluff with a fork and serve!
You can also cover the pot with a towel and let sit. The longer it sits, the more fluffy and delicious the buckwheat!