Partially Cook Bacon; Drain On Paper Towels. Cut A 1/4-In. Lengthwise Slit In Each Hot Dog; Place Cheese In Each Slit. Starting At One End, Wrap Bacon In A Spiral Around Hot Dog; Secure With Toothpicks. Split Buns Just Halfway. Combine Butter And Mustard; Spread Inside Buns. Set Aside. On A Covered Grill Over Medium Heat, Cook Hot Dogs With Cheese Slide Down For 2 Minutes. Place Buns On Grill With Cut Side Down; Grill Until Lightly Toasted. Remove Toothpicks From The Hot Dogs; Serve In Buns With Onion And Chilies If Desired.