Freeze overnight (or up to two weeks if you are worried about parasites in the liver).
Put cubes into a freezer bag and store it in the freezer.
Each night, I take one cube out and put it in a small dish in the fridge. In the morning, the cube is a nice soft mush-ball of liver and fish. YUM! I scoop it up with a spoon and chase it down with kombucha to hide the taste. I have even been known to chase it with a small piece of chocolate. Hey, it’s good for the baby!