In a large bowl, soak the rice noodles in hot water for 10 minutes, then drain. Cut the noodles into 4-inch lengths.
In a medium bowl, mash the tofu until it resembles cottage cheese. Mix in the turkey, water chestnuts, scallions, ginger, 1/3 cup of the cilantro, 1 tablespoon of the soy sauce, 1/2 teaspoon of salt and 1/4 teaspoon of white pepper. Form into 1-inch balls and transfer to a plate. Cover with plastic and refrigerate.
Heat the oil in a small skillet. Add the shallots and cook over moderate heat, stirring constantly, until golden, 7 to 8 minutes. Drain on paper towels.
In a large saucepan, combine the stock with the chile, lime juice, sugar and the remaining 1 tablespoon of soy sauce. Season with salt and pepper and bring to a boil. Reduce the heat to moderately low, add the meatballs and cook for 3 minutes. Stir in the bok choy and tomato and cook for 1 minute. Add the rice noodles and cook over moderate heat until slightly softened, about 2 minutes. Ladle the soup into bowls, garnish with the fried shallots and the remaining 1/2 cup of cilantro and serve.