Preheat the oven to 400F.
Peel the squash, remove the seeds and membrane. Cut squash into 2″ chunks.
Peel and core the pears. Cut into quarters.
Toss the squash and pears with olive oil, salt, pepper, and sage. Place in roasting pan.
Roast the squash and pears in the preheated oven for about 45 minutes, until they are very soft.
In a pan, heat some olive oil.
Add the diced onion and garlic.
Cook, stirring occasionally, until the onion is transparent, about 5-7 minutes.
Working in batches and filling the blender no more than halfway full, place in the blender some of the roasted squash and pear, onion and garlic, and chicken stock. Pour into a large soup pot.
Puree the rest of the ingredients in batches until smooth.
Heat through and serve.