Preheat an outdoor grill for medium-high heat, and lightly oil the grate.
Mix the mayonnaise and curry powder together in a small bowl until well combined. Set aside.
Carefully slice the chicken breasts in 1/4 inch thick strips. Brush each strip with melted butter and lightly sprinkle with garlic salt. Grill the chicken strips until they are a nice browned color, about 5 minutes on each side.
Lightly toast the hoagie rolls on the grill. Lightly spread about 1 teaspoonful of the curry mayonnaise on each side of the hoagie roll. Place 1-2 chicken strips on each roll. Put 1/4 cup of the cabbage on top of the chicken.