Heat the olive oil in a heavy-bottomed soup pot or Dutch oven. Add the chopped onions and carrots, and cook, stirring occasionally, for 5 minutes until the vegetables start to soften.
Season the vegetables with sea salt, ground black pepper, and minced garlic.
Add the sausage to the pot, breaking it into smaller chunks as it cooks. Once browned completely, tilt the pot to remove any excess fat if necessary.
Mix in the chicken broth, pumpkin puree, minced sage, grated nutmeg, heavy cream, and brown sugar. Bring the mixture to a simmer and cook for 20 minutes.
Adjust seasoning as needed and serve with a sprinkle of roasted pumpkin seeds on top.