A lusciously tart sauce of sauteed mushrooms, onions and sour cream is beefed up and served over tender egg noodles. Hint: do not bring the sour cream sauce to a boil.

A lusciously tart sauce of sauteed mushrooms, onions and sour cream is beefed up and served over tender egg noodles. Hint: do not bring the sour cream sauce to a boil.