There's a NY Times article on Yakisoba which explains its origins (China) and suggests different recipes:
The noodles are the easy part: contrary to what you might assume from the name, yakisoba doesn’t contain soba but usually noodles called chukamen, made with wheat flour and egg. Chukamen are similar to ramen or Chinese egg noodles; they’re yellow, and sold fresh or dried. The sauce is trickier. Recipes use everything from applesauce to mustard, neither of which works for me. I like a mix of ketchup, soy sauce, Worcestershire sauce, mirin and Tabasco. There are those who insist that ketchup has no place in Japanese cooking. No doubt they’re right, but yakisoba is different. The other ingredients are up for grabs. Very thinly cut pork is ideal, I think, but chicken, beef, shrimp or tofu, or a combination, is perfectly acceptable. Shredded Napa or savoy cabbage cooks down quickly and adds a fresh crispness in contrast to the noodles, but there’s no reason not to use mung bean sprouts, bamboo shoots, mushrooms or any other quick-cooking vegetable.
I'm sorry, but ketchup is not the critical ingredient here - Worcestershire sauce is for sure. They use this in Korean cooking as well for a variety of things that require a dark richness to them like yakisoba does. It's probably England's greatest contribution to world food (- although Chicken Tikka Masala and Bacon and Eggs would be close behind).
Posted by: Edward | March 11, 2010 at 06:29 PM
Well, that's a quote from the article. I don't eat it as often as I should since I really love yakisoba.
Posted by: MC | March 12, 2010 at 01:18 PM