I've been making cabbage rolls for years but I came up with the hole saw idea not that long ago. The hole saw quickly separates the leaves of the cabbage from the cabbage core with a nice clean cut.
Step 1: Video Shows Ingredients and Process
Step 2: Coring Cabbage and Steaming
Step 3: Peeling Off Leaves
Step 4: Preparing Filling and Rolling
Step 5: Prepare for Cooking and Serving