Butternut Squash without tenders

1 tablespoon butter 3 1/2 cups cubed peeled butternut squash (about 1 1/2 pounds) 3/4 cup chopped carrot 1/2 cup chopped sweet onion 2 1/2 cups fat-free,[...]

3 cups (1/2-inch) cubed peeled butternut squash, divided 3 1/2 cups fat-free, lower-sodium chicken broth 2 cups uncooked Arborio rice 2 tablespoons chopped[...]