This easy casserole is made with fresh lean pork or leftover pork roast. The pork is browned with onion and celery, and then it's combined with cooked rice. Use a small boneless pork loin roast or some lean country-style pork ribs. Feel free to add steamed peas and carrots to the mix for some extra color and flavor. Serve this pork and rice casserole with a tossed salad or other steamed vegetables.