This dish did not originate in Singapore, so how it came to be named is something of a mystery. But the thin, fragrant, sunny-colored noodles tangled with egg, tender-crisp vegetables, shrimp and char siu (Cantonese roasted pork) have become a popular menu item in many Chinese-American restaurants. Our simplified version has no pork; the eggs and shrimp provide plenty of substance. The correct noodle to use here is thin, wiry rice vermicelli or rice sticks, sometimes labeled maifun.