Heat the olive oil in a large pot or Dutch oven over medium heat. Add the diced onion and sauté for about 5 minutes, until softened.
Stir in the minced garlic and cook for an additional 1 minute until fragrant.
Add the ground lamb or beef to the pot, breaking it up with the wooden spoon. Cook until browned, about 5-7 minutes. Drain any excess fat if necessary.
Add the diced carrots, celery, thyme, and rosemary to the pot, stirring well. Cook for another 5 minutes to allow the vegetables to soften.
Pour in the beef broth, add the frozen peas, tomato paste, Worcestershire sauce, and diced potatoes. Stir well to combine.
Bring the soup to a simmer, then reduce the heat to low. Cover and cook for about 20 minutes, or until the potatoes and vegetables are tender.
Season with salt and pepper to taste. If desired, use a ladle to serve the soup into bowls and garnish with fresh parsley.