Heat the oil in a pot over medium heat. Saute the onion, mushrooms, carrot, celery, and garlic until the onion and mushrooms soften. Stir in the flour until fully combined.
Stir in the broth, thyme, sirloin, and barley. Season with salt and pepper.
Bring to a simmer until the barley is tender, about 20-30 minutes (refer to the instructions on the package for cooking time). Taste and adjust the seasoning as needed. Add more broth if needed.
Remove the thyme before serving. Garnish with parsley. Serve with crackers.
Notes
Pro Tip: Make a bigger quantity and freeze what's left or utilize it throughout the week. Freeze or use within 5 days.