Saute the diced onion, celery and shredded carrot in the 2T olive oil for about 3 to 4 minutes until softened.
Add the ground beef and season with salt and pepper, cook until no longer pink
Add the minced garlic and cook until fragrant, stirring so it doesn't burn
Add the broth, diced tomatoes, tomato paste, potatoes or pearl barley (if using), oregano and worcestershire, taste for seasoning and adjust if necessary. Cook for 10 minutes or until all of the veggies are fork tender.
Add extra veggies at this time. I added 1.5 cups of shredded brussel sprouts this time, but you could add shredded cabbage, frozen mixed veggies, fresh green beans or any other veggie that you have on hand that would go well in soup (cauliflower, broccoli)
Let the soup simmer for 20 minutes to cook the vegetables completely and let the flavors combine.