Beijing's own zhájiàng miàn (fried sauce noodles) is essentially spag bol with Chinese characteristics: wheat noodles, a dollop of sauce made from pork and soybean paste, and extras like chopped radish, soybeans and cucumber on the side, which you mix together. The dish is a menu mainstay all over town, but here it's front and centre, along with other old Beijing snacks.
The King is stranded in a neighbourhood of apartment blocks. Walk south along the main road from the subway exit and turn left onto Dongxinglong Jie. You'll see it after 300m on your left.