In a large sauce pan on medium high heat, add the oil and bring to shimmering.
Add the beef to brown, 2 mins, remove from the pan and reserve
Place the pan back on the heat and add the onion, celery, and carrots and cook about 5 mins. to tenderize, If the pan is somewhat dry, add 1/4 cup of the chicken broth.
Next, add the sliced mushrooms and cook an additional 4 mins.
Add the beef broth, chicken broth, quick barley and thyme bundle and bring to a boil.
Cook for 12 minutes for the barley to soften
Add the beef and taste and adjust seasonings, (I added 1/2 tsp salt and 1 tsp ground black pepper)
Remove the thyme bundle and serve