Preheat oven to 400 F degrees.
Drizzle avocado oil over butternut squash and spread the cubes on the baking sheet in a single layer. If using the whole squash, poke several holes in different parts of the vegetable and drizzle with oil, then put in the oven.
Peel and cut onion in 2 halves. Add to the butternut squash on the baking sheet. Take it out of the oven after about 10-15 minutes or when caramelized and soft.
Roast the squash for 25-30 minutes until it can be easily pierced with a fork.
If using a whole squash, let it cool and cut it in half. Using a tablespoon, scoop out the seeds to a separate bowl (the seeds can be washed, roasted, and ground to be used in other dishes instead of breadcrumbs). Scoop out the flesh of the vegetable, discarding the skin.
Add chicken broth, butternut squash, onion, garlic to a pot, cover and bring to a boil.
Using a handheld blender, blend all the ingredients in a pot.
Reduce the heat and add salt, pepper, nutmeg and thyme. Cook for another 2-3 minutes and take the pot off the heat.
Pour into bowls and serve immediately.