Bring broth, onion, and sugar to a boil over high heat. Add peas and cook until tender, about 3 minutes. Drain. Discard liquid and onion slices and set peas aside.
Heat oil in a large skillet over medium heat. Add pine nuts and cook, stirring, about 3 minutes or until golden brown. Add rosemary, then peas and saute until heated through. Season with salt and pepper and serve.