Heat the olive oil in a large pot over medium heat.
Add the diced yellow onion and sauté for 5-7 minutes until soft and golden brown to build a deep roasted base.
Stir in the minced garlic, sea salt, black pepper, cinnamon, and nutmeg, cooking for 60 seconds until the spices become fragrant.
Add the pumpkin puree to the pot and stir constantly for 2 minutes to slightly toast the puree and deepen the flavor.
Slowly pour in the chicken bone broth and whisk until the mixture is completely smooth and combined.
Bring the liquid to a light simmer, then reduce heat to low and cover for 10 minutes to allow flavors to meld.
Stir in the cooked shredded chicken breast and continue to simmer for 3 minutes until the chicken is heated through.
Remove the pot from the heat and stir in the Greek yogurt until the soup is creamy and velvety.
Ladle into bowls and serve immediately.