Add the oil to a large pan or pot over medium-high heat.
Once it begins to smoke lightly, sear the beef until lightly browned, which takes about 1 to 2 minutes per side. Set aside on a plate.
Add the butter to the pan and cook the onions and mushrooms until caramelized, which takes about 8-10 minutes.
Add the garlic and saute for 1 to 2 minutes before putting the beef back in the pan.
Deglaze with brandy and cook until it’s almost gone. This takes about 2 to 3 minutes for it to be fully absorbed.
Pour in the beef stock, add in the bay leaves and mustard, and cook on medium-high heat for 8-10 minutes or until the liquid is reduced by 1/3.
Finishby whisking in the sour cream, salt, pepper, and parsley.
Toss with noodles and garnish with extra parsley.
Notes
Make-Ahead: This is meant to be eaten as soon as it's finished cooking.How to Store: Cover it and keep it in the refrigerator for up to 4 days. It will freeze covered in plastic for up to 2 months. Thaw for 1 day in the refrigerator before reheating.How to Reheat: Add the desired amount to a medium-sized pot with a bit of beef stock and cook over low heat until hot.In my opinion, adding caramelized mushrooms and onions elevates the recipe, bringing out a more delicious umami flavor in addition to only having meat in it.Other cuts used are bottom round or chuck roast, which would be better in a crockpot stroganoff so that it could cook for longer periods to help tenderize.Addingthe beef, mushrooms, onions, and garlic helps to flavor the sauce even more.The pan or pot must be large to help caramelize all the different ingredients, requiring a lot of surface area.Making this in the slow cooker is a great option if you don’t have time to stand in front of the cooktop, plus the meat is really tender.