Heat a grill to medium (350° to 450°).
Meanwhile, in a large bowl, combine olive oil, rosemary, salt, and pepper. Add halibut and bread. Toss to coat, then set aside 5 minutes.
Skewer an end of 1 strip pancetta, then alternate fish and bread cubes on a 10-in. metal skewer*, weaving pancetta between them. Repeat 3 times.
Grill kebabs, turning frequently, until fish is cooked through and bread is charred in places, about 6 minutes.
*You will need 4 metal skewers for the kebabs.
Note: Nutritional analysis is per serving.