Move oven rack to lowest position. Heat oven to 450°F. Spray 12-inch pizza pan with cooking spray.
Heat 10-inch skillet over medium-high heat. Add oil; rotate skillet to coat bottom and side. Cook chicken in oil 3 minutes, stirring frequently. Stir in bell pepper and onion. Cook 3 to 4 minutes, stirring frequently, until vegetables are crisp-tender and chicken is no longer pink in center; remove from heat. Stir in salsa; set aside.
Stir Bisquick mix and very hot water in small bowl until soft dough forms; beat vigorously 20 strokes. Press dough in pizza pan, using fingers dipped in Bisquick mix; pinch edge to form 1/2-inch rim. Sprinkle 3/4 cup of the cheese over crust. Top with chicken mixture. Sprinkle with remaining 3/4 cup cheese.
Bake 12 to 15 minutes or until crust is brown and cheese is melted and bubbly.