Creamy Butternut Squash and Carmelized Onion Soup

Last weekend I made this soup for some friends as an appetizer and it overshadowed the rest of my dinner party. Everyone was asking for seconds and thirds so much so that I did not have any left to take pictures. Instead, I had to make some more today(Such an easy soup that this is not a hard task)
Ingredients
1 medium butternut squash
3 large or 5 medium onions
4 cups stock( chicken or vegetable )
salt
1 cup greek yogurt
Pam
Parmesan rind

1. Cover a cookie sheet with aluminum foil and them pam the aluminum foil
2. Cut the top and bottom off a butternut squash and then cut in half and remove the seeds with a spoon.

3. Cut onions into 1/8th pieces.
4. Put the squash cut side down on cookie sheet and onions in middle.

5. Bake in over at 350 degree for about 90 minutes until the squash is soft occasionally mixing around the onions with tongs ( about every 30 min)

6. Once squash is soft all over remove the sheet from the oven and allow to cool.
7. Once cool add onions to soup pot and then remove flesh of squash from skin and add squash to soup pot.
8. Add 4-5 cups of stock and add in 1 inch piece of Parmesan rind
9. Blend with immersion blender until smooth and add salt to taste
10. Heat back up over medium
11. Once hot blend again with immersion blender while adding 1 cup of plain greek yogurt.
12. Serve to friends, have friends ask for recipe