Heat olive oil in a large soup pot over medium heat. Add the onion, carrots, celery and garlic and cook until softened but not browned, stirring often, about 7-8 minutes.
Add the roasted squash cubes, apple cubes, thyme and sage leaves and season with salt and pepper to taste and mix until well combined.
Add the chicken broth and bring to a boil. Reduce the heat to medium-low and simmer, stirring occasionally until the apples are tender, about 20 minutes.
Remove the soup from the heat. Puree the soup in small batches in a blender or by using an immersion blender. If using a blender, DO NOT overfill. Thin soup with additional broth, if desired.
Ladle the soup into bowls and top with blue cheese crumbles, toasted walnuts and or toasted pepitas, if desired.