Heat oven to 375 degrees. Lightly spray 13x9 baking dish with cooking spray.
Cut chicken breasts into bite size pieces-refrigerate.
Separate dough into quarters and place on wax paper- sprinkle with 2 tbsp. of fajita seasoning mix and toss to coat- put aside.
Heat large skillet over medium heat. Add peppers and onions, cook 3-5 minutes, stirring occasionally, until peppers and onion blister and char a little. Remove from skillet - keep warm.
Return skillet to heat- add oil and chicken and cook on each side until no longer pink in center. Sprinkle remaining fajita mix over chicken. Add water and cook and stir until sauce thickens. Return peppers and onions to skillet to coat.
Spoon chicken, peppers and onions into baking dish.top with seasoning coated biscuit pieces.
Bake 20 minutes until the biscuit pieces are thoroughly baked nd light golden brown. Sprinkle cheese over top and bake 5 minutes longer until cheese is melted.