Slice the onions and the mushrooms. Melt the oil and butter together in a cast iron casserole pan over a medium heat.
Saute the onions and mushrooms for a good 5 minutes until well softened and starting to brown.
In the meanwhile, dice the beef.
Remove the mushroom mixture from the pan and set aside.
Brown the meat in the hot pan until slightly catching. Scrape to remove all those yummy bits.
Add the brandy and cook it off to remove the alcohol taste.
Add seasoning and then the stock, worcestershire sauce, bay leaf, mustard and return the mushroom mixture to the pan.
Cook for approximately 5-6 minutes until the beef is cooked through. Turn off the heat and cover while you make the mash. OR, continue with the recipe if you are already organised with the mash.
When ready to serve, add the sour cream and diced pickles and stir through to combine. Serve over the mash (or puree).
It is perfectly acceptable to serve Stroganoff with flat noodles, but my Russian great great grandmother would potentially turn over in her grave. I do love strog with noodles. But on this occasion I went with the more politically correct (these days) Cauliflower Mash or puree. You know you can use regular mash as well right? Whatever does it for you!