Pour broth into large saucepan set over high heat; bring to boil. Add quinoa and cook for 15 minutes or until tender.
Reduce heat to medium-low. Whisk eggs with lemon juice until frothy. Ladle about 1 cup (250 mL) hot broth into egg mixture. Whisk mixture back into simmering saucepan.
Cook, stirring, for 1 to 2 minutes or until soup is slightly thickened. Season with salt and pepper, to taste. Garnish each serving with parsley and Parmesan.