1. In a large bowl, combine the flour, water, salt and vegetable oil. Knead the dough by hand for 10-15 minutes until smooth, like pizza dough. Let it rest for at least 30 minutes.

2. Bring the water to a boil in a pot. Add the dried anchovies and dried kelp. Cover and cook over medium heat for 20 minutes.

3. Add the potatoes and onions to the pot. Cook for 15 minutes over medium heat. Turn off the heat. Use a slotted spoon to remove the anchovies and kelp.

4. Fill a small bowl with cold water and keep it nearby. Turn the heat back to medium-high. Pick up the dough ball and hold it in one hand. Dip the fingers of your other hand into the cold water to prevent sticking.

5. Pull and stretch a 3-inch portion of the dough using your wet fingers, making it as thin and wide as possible. Tear off the stretched portion and drop it into the boiling soup. Repeat the process quickly, tearing pieces from the dough ball until all the dough is used.

6. Stir the noodles gently with a ladle to prevent them from sticking together.

7. Add the garlic, zucchini, carrot, green onion and fish sauce. Cover and cook for 5 minutes until the noodles float to the surface and are fully cooked.

8. Remove the pot from heat. Stir in 1 teaspoon of the sesame oil.

9. Ladle the soup into individual bowls. Serve immediately.