Peel, clean, and chop butternut squash into 1 inch cubes. Toss with olive oil and cinnamon, then place in dutch oven or baking dish. Lightly season with salt and pepper.
Bake for 25 minutes at 400˚F, to lightly caramelize the squash.
If using a baking dish, transfer contents to large pot. Add diced onion, carrots, and stock to dutch oven. Bring contents to a boil, then reduce to a simmer for 15 minutes.
Using an emersion blender, puree contents until smooth. Stir in half-and-half and ground nutmeg.