Cut pork into cubes and fry to brown. In same pan as the pork was fried in, fry onion and celery to transparent. Add chop suey vegetables, rinse out can and add 1/4 can water to vegetables and meat. Simmer 1/2 hour to 45 minutes. Mix soy sauce, sugar and flour to meat and vegetable mixture to thicken. Serve over cooked rice.