Rinse rice well and low boil until tender. Drain any remaining water. In a heavy pot, melt butter. Add onion and mushrooms. Saute for 5 minutes or until onions are transparent. Add broccoli, carrots and chicken broth. Simmer until vegetables are tender. At this point, either turn the entire pot of vegetables into a blender or food processor until smooth, or process about one half and leave the rest whole, or leave all vegetables whole. Continue heating and cook until thickened. If you do not process the vegetables, you might wish to add a small amount of arrowroot powder or cornstarch to thicken the broth. Add the chicken and wild rice. Add salt and pepper to taste.