Ukrainian
Rinse the buckwheat in a sieve until the water runs clear and let it drain.
Bring the water to a boil with 1 tsp of the salt, add the buckwheat, cover and cook over low heat for 15-18 minutes until the water is absorbed.
Meanwhile, heat 2 tbsp of the oil in a large frying pan and fry the onions over medium heat for 6-7 minutes until golden.
Add the remaining oil and the mushrooms, raise the heat and fry for 10-12 minutes, stirring, until their liquid evaporates and they brown.
Season the mushrooms with the remaining salt and the pepper.
Stir the butter into the hot buckwheat, then fold in the mushrooms and onions, cover and leave for 5 minutes.
Sprinkle with dill and serve hot, on its own or as a side with a vegetable salad.