In a large pot, heat the olive oil over medium-high heat. Add the beef stew meat and brown on all sides, about 5-7 minutes. Remove the beef and set aside.
In the same pot, add the chopped onion, carrots, and celery. Sauté until the vegetables are softened, about 5 minutes. Stir in the minced garlic and cook for an additional minute.
Return the browned beef to the pot. Pour in the beef broth and water. Add the pearl barley, thyme, rosemary, bay leaf, salt, and pepper. Bring to a boil.
Reduce the heat to low, cover, and let simmer for about 1 hour, or until the beef is tender and the barley is cooked.
Stir in the frozen peas and cook for an additional 5 minutes. Remove the bay leaf before serving.
Ladle the soup into bowls and garnish with fresh parsley.