Heat 1/2 cup olive oil over medium heat in a 10- to 12-inch skillet. Add the garlic and cook until golden. Using a slotted spoon, remove and discard the garlic. Working in batches, add a single layer of beef cubes to the skillet and sear on all sides. Rem
In a 10-quart soup pot, bring the stock or broth to a simmer. Add the browned beef and rinsed barley, cover, and return to a full simmer. Reduce heat and cook gently for about 1 1/2 hours.
Return the skillet to medium heat and add 2 tablespoons of olive oil. Heat and add the onion, leek, celery, carrots, and potatoes. Stir in the oregano and thyme. Cover the skillet and cook over very low heat for about 15 minutes.
Transfer the vegetables to the simmering soup, then add the chopped tomatoes. Simmer for 15 minutes before serving.