In a large bowl, stir together broth, sugar, soy, and sherry.
Add pork and turn to coat.
Cover and refrigerate until next day, turning several times.
Barbecue meat by indirect heat
Lift meat from marinade and drain briefly (discard marinade).
Place meat on grill directly above drip pan.
Cover barbecue and adjust dampers as necessary to maintain an even heat.
Cook until a meat thermometer inserted in thickest part registers 170°F (2 to 2 1/2 hours).