Spray same skillet with cooking spray. Add chicken, green onions and cream cheese; cook over medium heat 2 to 4 minutes, stirring occasionally, until cheese is melted and mixture is combined. Stir in taco seasoning mix and water. Cook over medium heat 1 to 2 minutes longer, stirring frequently, until mixture is hot and bubbling at edges. Remove from heat; stir in Monterey Jack cheese.