Heat the olive oil in a large pot over medium heat. Add the ground beef and cook until browned, breaking it up with a spoon as it cooks.
Add the onion, carrots, and parsnip to the pot. Cook for 5 minutes until the vegetables start to soften.
Stir in the garlic and thyme and cook for 1 minute until fragrant.
Pour in the beef broth and diced tomatoes. Add the potatoes and bring the mixture to a boil.
Reduce the heat to low, cover the pot, and simmer for 25 minutes until the potatoes and other vegetables are tender.
Taste and season with salt and black pepper before serving or cooling for storage.