Toss the beef with flour, salt, and pepper.
Brown the beef in olive oil and transfer it to the slow cooker.
Add the onion, garlic, carrots, celery, and potatoes.
Whisk together the broth, tomato paste, Worcestershire sauce, thyme, and rosemary, then pour over the ingredients.
Add the bay leaves and cook on Low for 8–9 hours or High for 4–5 hours.
Stir in the peas during the last 30 minutes.
Mix the cornstarch with cold water, stir it into the stew, and cook until thickened.
Remove the bay leaves, garnish with parsley, and serve hot.