late) Remove mussels w/slotted spoon & cool. Strain liquid through srainer lined w/several layers of cheesecloth. sholud be 3cups. Break up noodles, cover w/hot water & soak, 10-15min. In heavy pot, heat oil. Add crushed chilies, zest, remaining garlic & ginger. Saute til tender, 1-2min; don't let ingredients brown. Add bok chou & white parts of scallion & cook another 3-4min, stir occasionally. Add clam juice, water, lime juice, fish sauce, soy sauce, sugar & strained mussel broth. Bring to simmer. While heating, remove mussels from shells ( reserve anu juice, strain & add liquid to soup; add mussels. Simmer another 2-3min, garnish w/cilantro & scallion greens.