Heat the olive oil in a large pan over medium-high heat. Season the stew meat generously with salt & pepper.
Cook the meat in a single layer for 4-5 minutes on each side or until golden brown. Cook in batches if need be.
Place the meat in a slow cooker along with onion powder, diced tomatoes, beef broth, bay leaves, and Italian seasoning. Add salt & pepper to taste.
Cook on LOW for 7 hours, or HIGH for 4 hours.
At the end remove 1/4 cup of stew liquid and add the flour. Whisk until smooth & return to the stew. Combine well.
Cook and cover on HIGH for an additional 30 minutes to slightly thicken your stew.
Uncover and stir in the frozen peas. Let sit for 5 minutes, and serve.