Step 1 procedure: Cut the beef into smaller pieces of your choice. The smaller pieces will cook slightly quicker. Larger pieces may make a nicer presentation when cooking is finished.
Preheat a large deep sided sauté pan or sauce pot over high heat. Add the clarified butter and then add the beef a few pieces at a time and turn it occasionally until it is deep brown on all sides. Remove the browned beef from the pan and continue to brown the remaining beef. Add the mushrooms and onions to the same pan and brown them over high heat. Add the white wine, balsamic vinegar, beef stock and the herbs and spices and reduce the heat to low. Return the beef and simmer uncovered for about 90 minutes until the meat is fork-tender and soft to the bite.
Step 2 - Roux procedure: When the meat is tender, increase the heat to medium and stir in the roux (mixture of butter & flour) a little at a time until the sauce thickens to a heavy consistency. Let the mixture simmer for 5 minutes, stirring occasionally to avoid scorching of the bottom. If the meat is very tender, you can remove it to a side plate during this process so that it won’t be torn apart by the stirring motion.
Step 3 procedure: Remove the pan from the heat and allow it to stop simmering. Stir in the sour cream. Adjust the seasoning, return the meat to the sauce if necessary, and return to the heat to warm to serving temperature.
Serve over your favorite starch with your favorite vegetable.