Corned Beef and Barley Soup with ribs

3 lbs corned beef brisket , cubed 4 tablespoons olive oil 2 quarts beef broth salt & freshly ground black pepper, to taste 1 teaspoon dried oregano 1 teaspoon[...]

6 celery ribs , chopped 4 medium carrots , pared and sliced 2 cups cubed peeled potatoes 5 cups reduced-sodium beef broth 3 cups cubed cooked corned beef 2[...]