Heat butter and oil over medium in a large skillet until butter begins to melt. Add onions and saute until soft, about 5 minutes. Add garlic and a pinch of salt and stir until garlic is fragrant. Add the mushrooms and soy sauce, stirring well to coat. Cover and cook until mushrooms are soft and have released their juices, about 10 minutes.

Uncover, add the white wine to deglaze the pan, along with another pinch of salt, and continue cooking until much of the liquid has evaporated. Add flour and stir to coat. Add the tomato paste, smoked paprika and another pinch of salt. Mix well.

Start the water boiling in a separate large pot for the egg noodles. Salt the water well. Add the noodles when the water boils and cook to package directions.

Add the stock 1/4 cup at a time. You want the sauce to be creamy, slightly thin, but not soupy. You might not use the entire one cup. Reduce heat to low-simmer, and allow to heat gently while the noodles cook.

Five minutes before you’re ready to serve, add the sour cream, stirring throughly to mix. Do one final tasting for salt and pepper (adjust if necessary). Top with parsley, and spoon over the noodles.