Bring a large pot three-fourths full of water to a boil. Gently pull the strands of noodles apart, then drop them into the boiling water, stirring to separate the strands. Bring to a second boil and cook for 1 minute longer. Pour the noodles into a colander and rinse thoroughly with cold running water. Drain well, shaking off excess water.
Pour oil to a depth of 2 inches in a small saucepan and heat to 375 degrees on a deep-frying thermometer. Meanwhile, pat dry 1 cup of the cooked noodles with paper towels. When the oil is hot, add the noodles. Using a pair of long chopsticks or tongs, stir gently to separate the strands and fry until golden brown, about 30 seconds. Lift out the noodles and place on paper towels to drain. Remove the pan from the heat. Crumble the noodles into small chunks and set aside.
Measure out 2 tablespoons of the oil used to fry the noodles and place in a large saucepan over medium heat. Add the garlic and sauté until browned, about 1 minute. Do not shake the cans of coconut milk before opening. There should be a thick layer of cream on top of each. Spoon off 1/2 cup of the thick cream from the top of each can and add it to the garlic. Raise the heat to medium-high and cook, stirring frequently, until the cream boils gently. Add the red curry paste, curry powder and turmeric and stir until smooth. Reduce the heat to medium and simmer until the mixture is thick and the oil begins to separate around the edges and rises to the surface, about 5 minutes.
Add the chicken, breaking it up into small pieces. Cook until the chicken becomes white, about 2 minutes. Raise the heat to high. Add the remaining coconut milk, the chicken stock, fish sauce, palm or brown sugar and cabbage and stir well. When the mixture begins to boil, adjust the heat to maintain a gentle boil and continue cooking for 8 minutes longer.
Divide the boiled noodles evenly among 6 warmed deep soup bowls. Stir the lemon juice into the hot soup and ladle equal amounts of the soup over the noodles. Garnish with the crumbled fried noodles, fried shallots, cilantro and green onions. Place a lemon wedge on top of each serving and serve hot.