MIX 3/4 cup orange juice and annatto paste. Pour over chops in shallow dish; turn to coat both sides of chops. Refrigerate 1 hour to marinate.
MEANWHILE, mix mayo, chiles and remaining orange juice in large bowl. Add cabbage, onions and radishes; mix lightly. Refrigerate until ready to serve.
HEAT grill to medium-high heat. Remove chops from marinade; discard marinade. Grill chops 5 to 6 min. on each side or until done (160ºF). Serve topped with avocados, with slaw on the side.