Start by peeling and cubing the squash into small, even pieces. Chop the onion, mince the garlic, and grate the ginger so everything is ready to go. Keeping ingredients prepped ahead makes cooking smooth and stress-free.
Heat olive oil in a large pot over medium heat, then add the chopped onion. Cook until soft and translucent, then stir in garlic and ginger for a fragrant base. This step builds the foundation of flavor for the soup.
Add the cubed squash to the pot and stir well to coat it with the aromatics. Pour in the vegetable stock and bring everything to a gentle boil. Let it simmer until the squash becomes tender and easy to mash.
Once the squash is fully cooked, remove the pot from heat and blend the mixture until smooth. You can use an immersion blender directly in the pot or transfer it carefully to a blender. The texture should be creamy and velvety.
Let the soup cool slightly before stirring in the miso paste to preserve its flavor. Add soy sauce and sesame oil, then taste and adjust salt and pepper. Stir well until everything is fully combined.
Return the soup to low heat for a gentle warm-up, but avoid boiling after adding miso. Serve hot with your favorite garnishes like herbs or chili flakes. The aroma alone will make it irresistible.