HEAT oven to 400°F.
HEAT oil in large skillet on medium-high heat. Add chicken; cook and stir 5 min. or until done. Stir in peppers, seasoning mix and water. Bring to boil; simmer on medium-low heat 10 min., stirring occasionally.
SPOON into 9-inch pie plate sprayed with cooking spray; sprinkle with cheese. Prepare muffin mix as directed on package; spoon over cheese, completely covering cheese layer.
BAKE 20 min. or until golden brown. Let stand 5 min. before serving.