In a large pot or Dutch oven, heat the olive oil over medium-high heat. Add the beef cubes and brown on all sides, about 5-7 minutes. Remove the beef and set aside.
In the same pot, add the chopped onion and garlic. Sauté for about 3-4 minutes until the onion is translucent.
Return the browned beef to the pot. Add the beef broth, carrots, potatoes, celery, thyme, rosemary, bay leaf, salt, pepper, tomato paste, and Worcestershire sauce. Stir to combine.
Bring the mixture to a boil, then reduce the heat to low. Cover and simmer for 1.5 to 2 hours, or until the beef is tender.
If using, add the frozen peas during the last 10 minutes of cooking. For a thicker stew, stir in the cornstarch mixture and cook for an additional 5 minutes.
Remove the bay leaf before serving. Adjust seasoning if necessary. Serve hot.