Preheat oven to 350°.
Combine first 10 ingredients in a medium bowl. Cut a horizontal slit through thickest portion of each breast half to form a pocket. Stuff 1/3 cup crawfish mixture into each pocket.
Melt butter in a large nonstick skillet over medium-high heat. Add chicken; cook 4 minutes on each side or until browned. Wrap handle of pan with foil; bake at 350° for 35 minutes or until chicken is done.