In a pot, heat oil over medium heat. Add in ginger, white part of spring onion and garlic and sauté until fragrant.
Add in tomatoes, carrot (if using) and a pinch of salt. Cover and cook, stirring occasionally, for about 5 minutes until the tomatoes are soft and mushy.
Add in stock and soy sauce. Bring to a boil, then cover and simmer for 15 minutes.
While the soup is simmering, bring a pot of water to boil, add in a generous pinch of salt and add in dried noodles. Boil until the noodles are soft. Drain and rinse the noodles briefly under cold water, then drain the noodles well and add into the soup. Turn up the heat and let the soup come to a rolling boil.
Beat the eggs in a small bowl then pour slowly into the boiling soup. Taste the soup and season with salt to your liking. Turn off the heat.
Divide lettuce between 2 serving bowls. Ladle the soup and noodles into the serving bowl.
Garnish with the green part of spring onion, drizzle with a few drops of sesame oil (optional) and serve immediately.
NOTES
- You can use egg noodles, ramen noodles or even fresh hand-made noodles for this dish. For fresh noodles, you can skip the boiling part and them straight into the soup. Boil for a few minutes until the noodles are cooked before adding in the eggs.- Make Ahead: Make the soup base ahead of time (until step 3). When about to serve, reboil the soup and proceed with remaining steps.