Add beef, potatoes, carrots, celery, onion, and garlic to a 6-quart slow cooker.
In a medium bowl, whisk together beef broth, diced tomatoes with juices, tomato paste, Italian seasoning, paprika, salt, and pepper, then pour over ingredients in slow cooker.
Cover and cook on low for 7-8 hours or on high for 4-5 hours until beef is very tender.
About 30 minutes before serving, add green beans and stir to combine, then continue cooking.
Stir in cornstarch mixture and frozen peas during the last 10 minutes of cooking to thicken the stew.
Taste and adjust seasoning with additional salt and pepper if needed before serving hot.