Play Chapter 1 with waterbending available. You will eventually arrive in an alley with an Equalist being a good guard. This is the area just after the Air Gate that can only be destroyed with airbending. If you approach him, he will disappear. However the waterbending will allow you to kill him from a safe distance. He will give you a cabbage. For the cabbage to count, complete the level. Look at your treasure screen to keep count of the number required. Play Chapter 2 with waterbending available. During the mission in an alley, you will encounter a guard that will disappear when approached. Take him out from a distance with waterbending and he will drop a cabbage. After doing so, or if he was missed, exit to the chapter selection screen then resume the chapter. You will begin in front of the guard again. Repeat the process as many times as needed, then complete the level. In Chapter 7, when in your astral projection form with your bending locked kill all the Equalists on the ground. You should get a cabbage. This can be difficult because of the three Mecha-Tanks.