Stir in minced garlic and cook for another 30 seconds before adding rinsed barley, Italian seasoning, thyme, salt, and pepper.
Pour in vegetable broth, diced tomatoes, and add the bay leaf. Bring to a simmer.
Cover and let simmer for about 25 minutes before adding the chopped potatoes. Continue simmering for an additional 20–35 minutes until barley is tender; add frozen green beans in the last 5 minutes.