The Wrought Iron Grill is a block, added in version 79, and is used over a firepit to cook six pieces of food at once.
To craft the grill, you need two wrought iron double ingots. Go in your anvil (must be iron or higher) and put in the double ingots. Next, select the grill pattern and hammer until the arrows are aligned.
To use the grill, you must first make a firepit. Then place two blocks on either side of it and place the grill on top. It should appear over the pit. Right click it and add your food - up to six items at a time. Note that the food must be 80 oz. or less. Any more than 80 will not be able to be placed inside. To split food, craft it with a knife (any kind), this will cut it in half.