Trim leaves and tough ends from broccoli stalks. Cut broccoli into flowerets by removing each head to include a small piece of stem. Cut off the stem and peel it with a vegetable peeler, then cut crosswise into 1/8-inch pieces to make "buttons.".
To steam broccoli, rinse flowerets and "buttons." Place steamer basket in large saucepan; add 1 inch of water. (Water should not touch bottom of basket.) Place "buttons" in steamer; top with flowerets and cover. Bring to a boil over high heat; steam 5-7 minutes until bright green and crisp-tender.
Meanwhile, combine lemon juice and cornstarch in small saucepan. Stir in chicken broth and cook over medium heat until mixture thickens and begins to boil, stirring constantly.
Arrange "buttons" around edge of warm serving plate. Place flowerets in center. Drizzle with lemon juice sauce; season with pepper. Garnish with orange slices, if desired. Serve immediately.