1Heat oven to 375°F. Cut thin slice from rounded side of pear halves, if necessary, so they'll rest level in pan. In 13x9-inch pan, arrange pear halves, cut sides up. Brush tops of pears with oil; sprinkle with salt, pepper and rosemary.
2Roast uncovered 15 minutes. Fill cored hollow of each pear half with 2 teaspoons cheese. Roast uncovered 10 to 15 minutes longer or until pears are tender and cheese is soft. Sprinkle with walnuts. Drizzle with additional olive oil if desired.