Boil potato until tender. Mash and mix with milk and butter. Set aside.

In a large soup pot or dutch oven, heat olive oil over medium-high heat.

Add the beef, onion, carrots, and bell pepper. Stir and cook until the meat is almost browned.

Add the minced garlic and continue to cook until the meat is completely browned.

Pour in the beef broth, oregano, salt, and black pepper. Whisk in the tomato paste and mashed potato.

Bring to a boil and then cover and lower the heat to a simmer. Let simmer for 30 minutes.

Serve hot.