Set a large soup pot or Dutch oven over medium heat and add the olive oil.

Add the onion, carrots, celery, and 1/2 teaspoon of the salt to the pot.

Cook, stirring every minute or so, for 6 to 8 minutes, until the vegetables are softened and the onion no longer looks raw.

Add the garlic and dried thyme to the pot.

Cook for 30 seconds, stirring, until the garlic smells fragrant.

Add the barley to the pot.

Stir for 1 minute so the barley is coated in the oil and vegetables.

Add the diced tomatoes with all of their juices to the pot.

Stir and break up any large tomato pieces with your spoon.

Pour the chicken broth into the pot and add the remaining 1 teaspoon salt and the black pepper.

Raise the heat to high and bring the soup to a boil.

Lower the heat to medium-low so the soup bubbles gently.