Prepare rice according to packages directions.
Melt butter in saucepan. Add onion and cook until transparent.
Stir in flour and continue cooking for 1 minute.
Gradually add broth and half and half. Cook, stirring continuously, until thickened.
Sprinkle in the salt and pepper.
Add rice, chicken, and parsley and combine well.
Spoon mixture into a lightly-greased 9x13 casserole dish.
Bake uncovered at 425 for 30 minutes or until bubbly.