Information for this recipe is approximate and derived by calculations based upon supplier information and available reference data. These values may change based on your final product, substitution and or addition of ingredients, or use of a particular cooking technique.
Set up grill for indirect cooking: For gas grill, preheat all burners on high. Turn one burner off; place food over "off" burner. Reset remaining burner(s) to medium-hot. Close lid. For charcoal grill, arrange hot coals around outer edge of grill; place disposable pan in open space; place food over open area. Close lid. Heat to medium-hot.
Stir together cranberry sauce and onion soup mix in microwave-safe bowl. Cover and microwave on HIGH until hot, about 1 minute.
Wash hands. Season roast with salt and pepper; place over indirect heat on grill.
Cook roast, basting with cranberry mixture every 10 minutes, 30 to 45 minutes or until done (internal temp 155°F). Let rest 5 to 8 minutes before slicing to serve.
Heat any leftover basting mixture to boiling. Stir and boil 5 minutes.