Cook the sausage, bell peppers and green onions in a stockpot over medium heat, crumbling the meat as it cooks, until the meat is browned, about 10 minutes. Drain if necessary.
Add the corn, cream and broth. Stir in the black pepper and xanthan gum. Continue cooking, stirring frequently, until the chowder starts to thicken, about 10 minutes.
Stir in the corn extract and turn heat to low. Let simmer for 10 more minutes, then season with salt to taste. Serve garnished with sliced green onions, if desired.