Almost every Cantonese noodle house restaurant in Chinatown has beef stew noodle soup. Try New Won Kok, May Flower or Sam Woo. At the May Flower you can have the soup, but I'm thinking maybe you'll also appreciate the beef stew hot pot too.
Mandarin Deli. The broth is rich and flavorful, the beef is cooked till it wants to fall apart. A sprinkling of scallions and cilantro. You can get it regular or spicy, with thick noodles or bean thread. Mmmmmmm I want some now!