Heat olive oil in a large pot over medium heat. Add the beef stew meat and brown on all sides, about 5-7 minutes. Remove the beef and set aside.
In the same pot, add the diced onion and garlic. Sauté until the onion is translucent, about 3-4 minutes.
Add the carrots, celery, and potatoes to the pot. Stir and cook for another 5 minutes.
Return the browned beef to the pot. Pour in the beef broth and add the corn, peas, thyme, rosemary, salt, and pepper. Bring to a boil, then reduce heat to low and simmer for 30-40 minutes, or until the vegetables are tender.
If you prefer a thicker chowder, mix the flour with a little water to create a slurry and stir it into the chowder. Cook for an additional 5 minutes until thickened.
Stir in the milk or heavy cream and heat through, but do not boil. Adjust seasoning if necessary.
Serve hot, garnished with fresh herbs if desired.