Boil the buckwheat in lightly salted water. Make sure that the grain is not overcooked to a homogeneous mass.
Transfer the chicken liver to a preheated frying pan. If desired, pre-cut it into small or medium pieces. Chop the onion and add to the liver. Fry them together over medium heat.
Add butter to the liver, stir well so that the butter melts and evenly soaks the liver. Leave under the lid for 5-10 minutes.
Add salt and pepper to the liver. Put the finished buckwheat in the pan with the liver, mix well and leave to simmer under the lid for another 5-8 minutes. If desired, add a little paprika or turmeric for spice.
Transfer the finished buckwheat with liver to serving plates. If desired, garnish the dish with cherry tomatoes and fresh herbs.