1. In a large saucepan, heat sesame oil over medium heat. Add onions, garlic, and ginger and cook, stirring occasionally, 10 minutes. Add water, cabbage, vinegar, and pepper to taste. Bring to a boil. Reduce heat to low, cover, and simmer until vegetables are tender, about 20 minutes.
2. In a cup, mix miso and 1/4 cup hot water. Stir into soup. Add tofu and heat through, about 5 minutes.
3. Heat vegetable oil in a saucepan until it registers 375 degree F on a thermometer. Break noodles into 6 portions and carefully drop in oil one batch at a time. Immediately remove with a slotted spoon and drain on paper towels. Garnish each serving with fried rice noodles. Makes 6 servings.