Set a 6 to 8 quart saucepot over medium heat. Add the oil to the pot. Liberally salt and pepper the beef chunks on all sides, then place them in the pot. Use a wooden spoon to stir and cook the beef chunks until they are browned on all sides, approximately 5 minutes.
Next, add in the mushrooms, onions, celery, carrots, garlic, and Italian seasoning. Stir and soften the vegetables for another 3-5 minutes.
Pour in the beef broth and tomato paste. Cover the pot and turn the heat to medium-low. Simmer for one hour, stirring occasionally.
Peel and chop the potatoes into 1-inch cubes. (If doing this ahead of time, place them in water, so they don't brown. Then drain right before using.) Add the potatoes and corn to the stew. Stir, then cover and simmer for another 20 minutes until the potatoes are cooked through and the beef chunks are very tender. Stir in the peas. Then taste and salt and pepper as needed.
