Place wine, stock, garlic, ginger, lemongrass, and lemon rind in a saucepan over high heat. Bring the broth to the boil then add the mussels and cook for 2 to 3 minutes or until the mussels have opened. Discard any mussels that don't open. Serve mussels in deep bowls with the broth and some bread. Garnish with chopped scallions.;