Grate 1 orange to equal 1 teaspoon grated rind; set aside. Peel and section oranges, removing seeds; set aside.
Place broccoli florets in a steamer basket over boiling water, and cook 3 to 4 minutes or until crisp-tender.
Melt butter in a nonstick skillet over medium-high heat; add onion and ginger, and sauté until tender. Remove from heat.
Toss together broccoli florets, onion mixture, 1 teaspoon orange rind, and orange sections in a large bowl. Stir in yogurt. Serve immediately.