Combine beef, celery, carrots, red onion, potatoes, salt, pepper, garlic, parsley, oregano, Worcestershire sauce, beef broth, and tomato paste in the crock pot. I used a 6 qt crockpot for this stew. Cook on LOW for 10 hours or on HIGH for 6-7 hours.

About 30 minutes before serving, mix the flour and the water together in a small dish and pour into the crockpot. Mix until well combined. This will add a nice thickness to the stew. Next add in your frozen peas and corn. Continue cooking covered for 30 minutes.