This dish is stir-fried tofu with pork luncheon meat with some vegetables. This dish has originated from the Okinawa prefecture. Pork luncheon meat like SPAM and TULIP brands are seldom eaten in the mainland Japan but it is common in Okinawa cuisine. Many Americans live in Okinawa due to the US military bases present in that area. This could be the reason why you can find present-day Okinawa recipes that include pork luncheon meats.