2.Combine cream cheese, pesto and pepper in a small bowl with a fork.
3.Cut a horizontal slit along the thin, long edge of a chicken breast half, nearly through to the opposite side. Open up each breast and place one-fourth of the filling in the center. Close the breast over the filling, pressing the edges firmly together to seal. Repeat with the remaining chicken breasts and filling.
4.Lightly beat egg white with a fork in a medium bowl. Place breadcrumbs in a shallow glass dish. Hold each chicken breast half together and dip in the egg white, then dredge in the breadcrumbs.
5.Heat oil in a large nonstick skillet over medium-high heat. Add chicken breasts; cook until browned on one side, about 2 minutes. Place the chicken, browned-side up, on a baking sheet coated with cooking spray. Bake about 20 minutes.