Heat olive oil in a large heavy pot or dutch oven over medium heat. Season beef cubes with salt & pepper and brown on all sides. For 2 pounds of meat I usually do this in 2 batches so I don't overcrowd the pan. Transfer meat to a plate and set aside.
Reduce heat slightly and add a touch more olive oil if needed. Add onion and carrots to the pot and cook for 2-3 minutes. Add the mushrooms, stirring occasionally, and cook until veggies have softened, approximately 10 minutes.
Add garlic, thyme, tomato paste and cook for 3-4 minutes. Add wine and bring to a boil, scraping up any brown bits on the bottom of the pot. Cook until reduced by half, 4-5 minutes.
Return beef to the pot. Add the chicken stock and water. Bring to a boil, reduce heat to low and simmer, covered for 1 hour, stirring occasionally.
After 1 hour add the barley to the pot and continue to cook, covered, for 30 - 40 minutes, or until barley is tender. Add frozen peas for the last 2-3 minutes of cooking. Turn off heat, stir in parsley and serve.
Recipe by FEASTS AND FOTOS at https://www.feastsandfotos.com/2011/10/28/beef-barley-soup/