Cut each chicken breast lengthwise into 2 or 3 strips. Combine 1/2 cup flour and salt in resealable plastic food storage bag. Add chicken strips and shake to coat with flour mixture. Melt butter in large skillet over medium heat. Remove chicken from bag and shake off excess flour. Brown chicken strips in batches 2 to 3 minutes per side. Place chicken into slow cooker.
Add chicken broth to skillet and stir in any browned bits. Pour broth mixture into slow cooker. Add onion, jalapeno peppers and oregano. Cover and cook on LOW 7 - 8 hours or on HIGH 3 - 4 hours or until done.
Combine remaining flour and cream in small bowl; stir to form paste. Stir into chicken mixture; cook on HIGH until thickened.
Spoon chicken mixture in center of flour tortilla. Top with 1 cheese slice; repeat. Fold up tortillas and serve.