In a large pot, heat olive oil over medium heat. Add diced onion and sauté for about 5 minutes until translucent. Stir in minced garlic and cook for an additional minute.

Pour in vegetable broth, then add diced potatoes and sliced carrots. Bring to a boil, then reduce heat and let simmer for 10-15 minutes until vegetables are tender.

Incorporate frozen pierogi into the soup. Stir gently and cook for an additional 5-7 minutes until the pierogi are heated through.

Stir in chopped fresh dill, salt, and black pepper. Taste and adjust seasoning. Serve hot, optionally topped with sour cream.