1. In a large soup pot, heat the olive oil. In batches, sear the cubes of meat on all sides. Transfer the seared meat to a plate and reserve, keeping warm.
2. To the same soup pot place in the onions, celery, carrots and garlic. Cook over medium – high heat until the onions are wilted. Add in the chili powder and cumin. Stir. Add in the crushed tomatoes and water. Add the seared meat back to the pot, as well as any juices that remain. Bring to a boil. Lower to a simmer. Skim any residue that rises to the surface and discard.
3. Add in the bay leaf and oregano. Add in the potatoes for the last 20 minutes of cooking and continue cooking until the potatoes are tender. Season with the salt and pepper. Add in the cooked pasta and serve.