Beefsteak with mushrooms and cooking cream

First, cut the meat into sticks, mushrooms into quarters, and chop the onion. In a pan, add sliced ​​meat to the butter and oil mixture, season with salt and pepper and fry, turning for 3-4 minutes. Take out the finished meat, put it in a warm place. Add the onion to the frying fat, season with salt and sugar, and stir and fry until the onion softens. Transfer the fried onion to a sieve, press it into a clean pan so that the sauce is smooth, add the champignons and fry over medium heat for about 3 minutes. Then add the meat, chopped parsley, cooking cream, stir and wait for the ingredients to warm up. The dish is ready, and you can serve it.