Heat olive oil in a large pot over medium heat until shimmering.
Add chopped onions and minced garlic to the pot. Cook, stirring occasionally, until the onions become translucent and fragrant, about 5 minutes.
Add chopped sweet potatoes and carrots to the pot. Stir well to coat the vegetables with the aromatics and cook for another 2 minutes.
Pour in the vegetable broth, ensuring the vegetables are covered. Raise the heat to bring the mixture to a gentle simmer.
Reduce heat to low, cover the pot, and let the vegetables simmer until tender, about 20-25 minutes. The vegetables should be easily pierced with a fork.
Use an immersion blender directly in the pot, or carefully transfer the mixture in batches to a blender, then blend until smooth and creamy. Be cautious with hot liquids.
Return the blended soup to the pot (if using a blender), then season with salt and pepper to taste. Stir well and heat through for another 2-3 minutes.
Once the soup is hot and seasoned to your liking, ladle it into bowls and serve immediately, enjoying the warm, velvety texture and vibrant color.