While squash is cooking, wash, destem and chop kale. When squash has about 15 minutes left, begin cooking the filling by placing 1 cup broth in pot or large skillet with a lid. Bring to a boil and add mushrooms, kale, frozen rice and seasoning (if using warm, cooked rice, wait to stir in at the end). Reduce heat to low and cover. Cook approximately 10 minutes, stirring a few times.