Heat the butter over medium heat in a 12-inch skillet. Cook and stir the onion in oil for 5 to 7 minutes or until beginning to brown. Stir in the rice.
Cook and stir for 1 to 2 minutes longer until the rice is lightly toasted. Transfer the rice mixture to a 4-quart slow cooker and add the squash.
Heat the broth in a saucepan or in a large microwavable container until steamy. Pour over the rice.
Cover and cook on High for 1 3/4 to 2 hours or until the rice is tender. Stir and continue to cook uncovered for 5 to 10 minutes longer or until almost all the broth is absorbed.
Stir the cottage cheese, rosemary, and pepper. Heat uncovered for 10 minutes longer or until heated through.
Transfer the risotto to a serving bowl. Garnish with the pomegranate seeds.