In a large soup pot heat oil over medium-high heat. Add bacon and cook until crisp. Remove with a slotted spoon to a paper towel.
In the bacon grease add onion and saute until translucent, about 5 minutes. Add garlic, Italian seasoning and sage. Stir and cook for about 1 minute.
Add butternut squash and chicken broth. Bring to a boil then reduce heat and allow soup to simmer for about 25 minutes or until the squash is very tender.
Turn off heat. Using a hand-held immersion blender puree the soup to a smooth consistancy.
Once the soup is pureed, add in beans, chicken, parsley, lemon juice, salt, pepper and red pepper flakes.
Serve with reserved bacon crumbled on top.
If you do not have an immersion blender you can use a regular blender just fill the blender only half way and work in batches. Blending hot soup in a full blender will result in soup all over your kitchen.
You can almost always find pre-cut butternut squash in most grocery stores. It will save you a lot of time!