First, steam the entire head of cabbage in a pot of boiling water, making sure to cut off the core first. Let the cabbage head boil for about 6-8 minutes -- if you notice leaves separating from the head, you can gently peel away the softened leaves with a long fork.
Drain the head of cabbage and peel the necessary amount of leaves when cool.
Grab a large bowl and combine the cooked rice, egg, milk, onion, garlic powder, ground beef, salt, and pepper. Scoop about a 1/4 cup of this mixture into the center of each cabbage leaf and roll them up, making sure to tuck in the ends.
Secure the rolls by using a toothpick or bakers/butchers twine.