Preparation Heat the oil in a medium-wide nonstick or cast-iron skillet over high heat until the oil shimmers. Add the pork belly, onion, and carrot and cook, stirring frequently, for about 30 seconds. Add the cabbage and cook, stirring, until it wilts slightly and the onion is lightly browned at the edges, about 3 minutes. Add the noodles and cook, tossing with tongs, until the noodles are heated through, about 3 minutes. As you toss, gently separate the strands. (If the noodles don’t separate easily, add a splash of water to the pan.) Add the sauce and continue to cook, tossing, until thoroughly coated, about 1 minute. Season with more sauce to taste, toss well, and transfer to a bowl. Top with the beni shoga, bonito flakes, and aonori. Eat right away. Cooks' Notes:At Japanese grocery stores, chukasoba are sold in the refrigerated section in bags with sauce packets, and labeled “yakisoba.” I typically ignore the packets and instead use the tastier Otafuku brand yakisoba sauce. Why don’t I make my own? Well, then the stir-fry would be a chore (you wouldn’t make your own ketchup for a burger, would you?) rather than a quick lunch or perfect late-night snack. From Mastering the Art of Japanese Home Cooking © 2016 byMasaharu Morimoto. Reprinted by permission of Ecco, an imprint of HarperCollins Publishers.Buy the full book from HarperCollins or from Amazon.