Chile Crab

Ginger 'Juice' 2 cups hot water 1 (1-inch) piece fresh ginger, peeled and sliced 1 (1 1/2 by 1 1/2-inch) chunk Rock sugar or 2 to 3 tablespoons soft brown sugar Chile Sauce 9 ounces water 5 tablespoons tomato ketchup 2 tablespoons light soy sauce 1 tablespoon sugar 2 teaspoons cornstarch Crab 4 tablespoons groundnut oil 6 large cloves garlic, finely chopped 2 tablespoons freshly grated ginger 3 medium red chiles, seeded and finely sliced 1 pound freshly cooked crab, inedible parts discarded, claws removed and cracked, legs removed, remaining shell chopped into quarters 5 ounces water 1 tablespoon fresh lime juice Egg Noodles 11 ounces fine egg noodles or dried yellow Shi wheat flour noodles*, cooked, drained and drizzled with a little sesame oil to prevent sticking 1/2 teaspoon dried chile flakes 1 tablespoon light soy sauce 2 spring onions, sliced lengthwise, divided Handful fresh cilantro leaves and stalks, roughly chopped, divided *Can be found at specialty Asian markets.