Dice onion and mushrooms, finely chop parsley.
Rinse buckwheat well — a sieve is handy for this — under running water. Let it drain.
Add to the pot, add water at a ratio of 100 ml per serving, bring to a boil.
Reduce the heat to minimum, cover tightly with a lid.
Cook for 15 minutes.
2. Start cooking meat
Heat 1 tablespoon vegetable oil over medium heat, add the onion and turkey slices, cook for a couple of minutes.
3. Cook mushroom
Add mushroom sauce seasoning and cook, stirring, for 1 minute, then add mushrooms.
Cook for 3–4 minutes, stirring occasionally, so the mushrooms brown properly.
4. Finish
Add a small pinch of salt and pour a glass of water carefully to the pot. Bring to boil, let it simmer lightly over medium/low heat for 10 minutes.
Check the sauce consistency after.
Off the heat and stir in sour cream.
Taste again for salt, then crack a generous amount of black pepper.
5. Serve
Divide buckwheat among plates, top with meat and mushrooms, spoon over sauce, finish with herbs.