Preheat oven to 350 degrees f and line a baking sheet with parchment paper.
Cut tops off pumpkins, then cut them in half.
Scrape out all of the seeds and guts.
Brush pumpkin flesh very lightly with avocado oil, or olive oil, and set face down on prepared sheet pan. Roast for 45 minutes.
Remove from the oven, let cool for a few minutes, then peel off skin. Set aside.
To a large saucepan over medium heat add 1 Tbsp avocado oil, or olive oil, onion, celery and garlic. Cook for 2-3 minutes, or until slightly browned and translucent.
Add remaining ingredients while stirring, including the pumpkin, and bring to a nice simmer.
Transfer soup mixture to a blender or use an immersion stick blender to puree the soup. Pour mixture back into pot.
Continue cooking over medium-low heat for about 10 minutes.
Garnish with Roasted pumpkin seeds, and/or a dollop of plain Greek yogurt, or coconut milk.