Mark Bittman has become my secret friend or at least, his books and recipes have done that. I have not been disappointed with any recipe, I have made because, he allows so much freedom to make each recipe your own.
The Minimalist: From a Simple Base, Endless Possibilities (March 25, 2009) adapted
1/3 cup ketchup or 3 tablespoons tomato paste and a pinch of sugar
1 tablespoon rice wine vinegar, more to taste
A few drops dark sesame oil (optional) (I used.)
A squirt of sriracha or other sauce, or a dried red chili to taste (optional)
1 scallion, chopped
1 pound egg noodles
Bring a large pot of water to a boil and salt it.
In a smaller pot, bring 6 cups of water to a boil. Reduce heat so that it simmers, steadily.
Add to the smaller pot, soy sauce, ketchup, vinegar, sesame oil if using and sriracha or chili, along with a pinch of salt. Stir and let simmer.
Add egg noodles to large pot. Cook according to package directions.
Taste broth and add more soy, salt, vinegar or heat as you like.
In the last three minutes, add scallions to broth.
Divide noodles into bowls and pour hot broth over all.
Yield: 4 servings.