Heat the large pot over medium heat and add the olive oil. Once shimmering, add chopped onion and sauté until translucent and fragrant, about 5 minutes.
Add the diced sweet potatoes and sliced carrots to the pot. Stir for a couple of minutes until the vegetables start to release their aroma and turn slightly golden around the edges.
Pour in the vegetable broth, ensuring it covers the vegetables. Bring the mixture to a gentle boil, then reduce the heat to low and let simmer for about 15-20 minutes, or until the vegetables are fork-tender and easily mashable.
Use an immersion blender to carefully blend the soup directly in the pot until smooth and velvety. If you don’t have an immersion blender, transfer the soup in batches to a regular blender, then return it to the pot.
Taste the soup and season with salt and pepper. Let it rest for a few minutes to allow the flavors to meld and deepen.
Serve the soup hot in bowls, optionally drizzled with a splash of olive oil or garnished with fresh herbs for extra flavor and presentation. Enjoy the velvety, comforting warmth with a vibrant orange hue and rich aroma.