Heat oven to 375°F. Spray large cookie sheet with cooking spray. Unroll dough onto cookie sheet; press to 8x12 inches.
In 10-inch skillet, heat oil over medium-high heat. Add chicken; stir in chili powder, salt and garlic; cook 3 to 5 minutes, stirring occasionally, until lightly browned. Add onion and bell pepper strips; cook 2 to 3 minutes longer or until chicken is no longer pink in center and vegetables are crisp-tender.
Spoon chicken mixture in 4-inch strip lengthwise down center of dough. Top with salsa; sprinkle with cheese. With scissors or sharp knife, make cuts 1 inch apart on long sides of dough within 1/2 inch of filling. Alternately cross strips over filling; press edges to seal. Brush with egg white.
Bake 20 to 25 minutes or until deep golden brown. Cool 5 minutes. Cut crosswise into slices.