Flatten chicken breasts between waxed paper to a 1/2-inch thickness.
In a small bow, combine the butter, cheese, green onion and salt, if used. Spread over the center of the chicken breasts.
Cut each chili in half. Remove seed and veins if a mild flavor is desired.
Place half a chili on each breast. Fold sides until forming a bundle. Secure with a toothpick, if desired.
On a plate, combine the crushed corn chips, oregano and chili powder. Dip chicken in melted butter. Then press into corn chip mixture coating well.
Place chicken seam-side down on a microsafe rack.
Microwave, uncovered, at HIGH power for 5 minutes. Rotate rack.
Microwave at HIGH power for 4 to 5 minutes. Let stand 5 minutes. Remove toothpicks. Serve.
TIPS: To soften butter, place in a microsafe dish. Defrost 15 to 30 seconds. If softening, 1 stick, unwrap if in foil wrapper, and defrost 30 to 40 seconds.
