1. Heat the oil in a large Dutch oven or soup pot over medium heat. Add the onion, carrots, and celery, cooking until softened, about eight to ten minutes.

2. Add the ground lamb or beef to the pot. Break it up with a spoon and cook until fully browned, about seven minutes. Drain off any excess fat.

3. Stir in the minced garlic, dried thyme, and rosemary. Season with salt and pepper, and cook for one minute until fragrant.

4. Pour in the red wine (if using) and let it bubble and reduce by half. Sprinkle the flour over the mixture and stir well to coat all the ingredients. Cook for one minute.

5. Slowly pour in the broth, stirring constantly to prevent lumps from forming. Bring the soup to a simmer, then reduce the heat to low, cover, and cook for fifteen minutes, allowing the flavors to meld.

6. Stir in the Worcestershire sauce, frozen peas, and corn. Cook for another five minutes until the vegetables are heated through. Adjust salt and pepper as needed.

7. While the soup simmers, combine the prepared mashed potatoes with the melted butter and cheddar cheese.

8. Ladle the hot soup into bowls. Top each serving with a generous dollop of the cheesy mashed potato mixture and garnish with fresh chives or parsley.