In a large pot, brown stew meat in olive oil.
Season with salt, pepper, and garlic powder. Once mostly cooked, about 10 minutes or so, add the flour and stir well as it browns a little. A nonstick pot works best for this stew to keep it from sticking to the bottom of the pot and burning.
Add the beef broth, water, onion, celery, carrots, and potatoes and season with salt, pepper, garlic powder, and oregano.
Bring to a simmer and cook till veggies are soft, about 30 minutes. Add the diced tomatoes and simmer for a couple more minutes to let the flavors blend.
Serve with skillet cornbread or a rustic loaf of crusty bread.