In a large pot, heat olive oil over medium heat. Add ground beef and cook until browned, breaking it apart with a spoon. Drain excess fat if necessary.
Add onion, carrots, and celery. Cook 5–6 minutes until softened. Add garlic and cook 1 more minute.
Stir in broth, potatoes, thyme, and parsley. Bring to a boil.
Reduce heat and simmer, partially covered, for 35–40 minutes until and vegetables are tender.
Stir in peas and lentils, and cook for an additional 5 minutes.