Creamy Chicken and Rice

4 cups cooked rice

1/2 cup butter

1/4 cup all purpose flour

2 cups milk

2 tsp chicken bouillon granules

1 tsp seasoned salt

1/2 tsp garlic powder

1/4 tsp pepper

5 cups cubed cooked chicken

12 oz Velveeta, cubed

2 cups sour cream

1 1/4 cups crushed Ritz crackers (about 32)

Spread rice into a greased 13x9; set aside.  In saucepan, melt 1/4 cup butter; stir in flour until smooth.  Gradually add milk, bouillon, seasoned salt, garlic powder and pepper.  Bring to a boil.  Cook and stir for 2 minutes or until thick and bubbly.  Reduce heat; add chicken, cheese, and sour cream; stir until cheese is melted.  Pour over rice.  Melt the remaining butter; toss with crackers.  Sprinkle over casserole.  Bake at 425 for 10-15 minutes.