To get this achievement you must catch a fish from a body of water, then cook it in a furnace. This must be done in survival mode. It can be done on any difficulty.
To begin you must craft a fishing rod. These require string and sticks. String can be acquired by killing spiders.
Then go and find a body of water. I recommend finding a river, lake, or sea that has at least 5x5x2. Press
or right click while looking at the water to commence fishing, you will see a bob fly into the water. It will float until you see a stream of bubbles go towards it. When the bubbles hits the bob you should press
or right click again.
Now you have a fish you need to cook it. To do this, go to a furnace and place both the fish and some fuel within. Once the fish is cooked retrieve it from the furnace and the achievement will pop.