Preparation

• In a small saucepan, combine the broth and dried porcini. Bring to a boil, remove from the heat, cover, and let steep for 30 min. With a slotted spoon, lift the porcini out of the broth; chop coarsely and set aside. Strain the broth through a cheesecloth-lined sieve and set aside.
  
  Strain the porcini-enriched beef broth to remove grit from the mushrooms. The porcini and their soaking liquid give the Stroganoff great depth of flavor.
• Heat 1 Tbs. each of the oil and butter in a large sauté pan or skillet (a 12-inch skillet is perfect) over medium-high heat. When the oil is hot, add the cremini mushrooms and sauté, stirring often with a wooden spoon, until the mushrooms are softened and well browned, 5 to 6 min. Take the pan off the heat and transfer the cremini to a bowl.
• Season the beef strips generously with salt and pepper and dredge them in the flour. Return the pan to medium-high heat and add the remaining 2 Tbs. of oil. When the oil is very hot, swirl to coat the pan and then add the beef, spreading it in a single layer and stirring with the wooden spoon so that it browns quickly on all sides, 1 to 2 min. Be sure not to overcrowd the pan; work in batches if necessary. Sauté the beef just long enough so that it browns slightly on all sides; don’t overcook it. Transfer the beef to the bowl with the cremini.
  
  Dredge the beef in flour to help it brown quickly in the pan. Photo: Amy Albert
• Still over medium-high heat, melt the remaining 3 Tbs. butter in the pan and add the onion. Sauté, scraping up the browned bits in the bottom of the pan with the wooden spoon, until the onion just begins to brown, 4 to 5 min. Pour in the reserved porcini soaking broth. Stir in the mustard and Worcestershire sauce and then add the porcini, cremini, and beef, along with any accumulated juices. Bring to a simmer while stirring. Cook just long enough so that the sauce thickens slightly, 1 to 2 min. Reduce the heat to low and stir in the crème fraîche, cooking just until heated through. Taste and adjust the seasonings. Serve over the egg noodles or fettuccine, sprinkled with the parsley.
  
  Stir in the crème fraîche and cook just until heated through.

Beef Stroganoff is delicious with egg noodles, but other starches make good side dishes, too, provided they can soak up the wonderful sauce. Try spaetzle (tiny dumplings), mashed potatoes, steamed new potatoes, or a simple rice pilaf.

Select a full-bodied red wine to go along with the Stroganoff, such as a Rioja, a Côtes du Rhône, a Grenache, or a Grenache-Syrah blend from Australia. All of these will complement and stand up nicely to the rich, intense flavors of the porcini, onion, and beef.

When I can get my hands on fresh chanterelles or morels, I substitute those for the cremini. Other variations can be less exotic: Instead of beef tenderloin, try other quick-cooking meat cuts, such as chicken breast or pork loin. For a Hungarian version, add some paprika in addition to the salt and pepper, try dill instead of parsley, substitute tomato paste for Dijon mustard, and use the traditional sour cream.