Set your ceramic planter in the yard where you want it. The finished ceramic fire bowl will be heavy and difficult to move.
Measure the height from the inside of the ceramic planter. Measure the height of the ceramic cooking bowl from the outside. Subtract the height of the ceramic cooking bowl from the height of the ceramic planter to get the height difference.
Fill the ceramic planter with sand 2 inches below the height difference. For example, if the height difference was 20 inches, fill the ceramic planter with 18 inches of sand. Set the ceramic cooking bowl inside the ceramic planter on top of the sand.
Place the mini barbecue grill over the top of the ceramic cooking bowl. Pour sand through the grill into the ceramic planter to surround the ceramic cooking bowl with sand. Fill to the top of the ceramic cooking bowl so the sand is level with it. The top of the ceramic cooking bowl and the level of the sand should be level with the mini barbecue grill and 2 inches lower than the top of the ceramic planter.
Light a fire inside the ceramic cooking bowl and use tongs to set lava rocks on top of the mini barbecue grill to fill in the top 2 inches of the ceramic planter. Leave space between the lava rocks so the fire can breathe.