Cut chicken into 1-inch chunks; season with salt and white pepper. Heat oil in large skillet over medium-high heat until hot. Add chicken, mushrooms, onions, red pepper and celery. Cook and stir until chicken is no longer pink in center. Remove chicken and vegetables; set aside. Melt butter in skillet until hot. Add rice and saffron; cook 2 to 3 minutes, stirring constantly. Add wine; stir until absorbed. Stir in 1 cup broth; cook, uncovered, until broth is absorbed, stirring frequently. Continue stirring and adding remaining 1 cup broth and water, one cup at a time; allow each cup to be absorbed before adding another, until rice is tender and has creamy consistency, about 25 to 30 minutes. Stir in cheese, olives, cream and chicken mixture; heat thoroughly. Serve immediately.
Medium grain rice will yield the best consistency for risottos, but long grain rice may be used.