01 -  Boil elbow macaroni in salted water until just al dente. Drain thoroughly and set aside. 
 02 -  Melt butter in a saucepan over medium heat. Add flour, whisking continuously for 1 minute. Pour in the milk gradually, whisking until a thick sauce forms, about 3 to 4 minutes. 
 03 -  Add shredded sharp cheddar, salt, and black pepper to the sauce. Stir until cheese melts and the sauce is velvety. 
 04 -  Stir the drained macaroni into the cheese sauce. Allow mixture to cool completely. 
 05 -  In a large bowl, blend the cooled macaroni mixture with cooked rice and Parmesan until fully integrated. 
 06 -  Form approximately 2 tablespoons of mixture into compact balls. Continue rolling until all mixture is used. 
 07 -  Roll each ball in flour, then dip in beaten eggs, ensuring full coverage. Finally, coat with panko breadcrumbs. 
 08 -  Heat vegetable oil in a deep frying pan or Dutch oven to 350°F. Fry the balls in small batches for 2 to 3 minutes until crisp and golden brown. 
 09 -  Transfer fried rice balls to paper towels to drain excess oil. Serve warm, accompanied by marinara sauce if desired.