Preheat your oven to 400°F (200°C). Spread the chunks of butternut squash on a baking sheet, drizzling with one tablespoon of olive oil and sprinkling with a pinch of salt. Roast for about 25-30 minutes, until tender and slightly caramelized around the edges.
While the squash roasts, heat the remaining tablespoon of olive oil in a large pot over medium heat. Add the diced onion and cook, stirring occasionally, until softened and translucent, about 5 minutes. Then, stir in the minced garlic and cook for another minute until fragrant.
Slice the mushrooms and add them to the pot. Sauté until they release their moisture and start to brown, about 8 minutes. Season with salt, pepper, ground cinnamon, and thyme to build depth of flavor.
Once the roasted squash is ready, add it to the pot with the sautéed vegetables. Pour in the vegetable broth, bringing the mixture to a gentle simmer. Cover and let simmer for 10-15 minutes to allow the flavors to meld.
Add the chopped kale to the pot, stirring until wilted. Using an immersion blender, carefully blend the soup until smooth and velvety. Alternatively, transfer the soup in batches to a blender, then return it to the pot.
Taste the soup and adjust seasoning with additional salt and pepper as needed. If the soup is too thick, stir in a splash more broth to reach your desired consistency.
Serve the soup hot, garnished with additional kale or a drizzle of olive oil if desired. The finished dish should be smooth, warm, and vibrant, with a cozy autumnal aroma.
