Roasted Butternut Squash Bisque

Preheat oven to 350 degrees F. Cut and peel squash into cubes. Oil a baking sheet and bake squash for 45 minutes.
Bring 3 cups vegetable stock to a boil while heating olive oil in another stockpot and cooking onions, carrots, potatoes and garlic for 10 minutes over medium-low heat. Pour stock over vegetables and cook on low for 20 minutes.
In a blender or food processor, blend roasted squash and vegetable soup mixture. Transfer back to stockpot and let simmer for 5 minutes, adding in yeast, salt and pepper.