I was cutting through Ueno Park the other day and came across lunch time vendors. My stomach grumbled and my feet followed the smell of grilled fish. As I walked closer, I could see the symmetry of the skewered fish around the charcoal pile.

Robatayaki is the art of grilling food in a irori hearth. An irori hearth is simply a central grill of sand and ash where binchotan charcoal is stacked in the middle to grill food. Yes binchotan, the high-carbon charcoal that burns without flame or smoke that all chefs revere.

Those of you who want to try this at home, DO NOT burn binchotan in your oven unless you want to spend several thousands of dollars to replace it. There is a reason why it binchotan always stacked in a sand or ash pit, just a little burns hot enough enough to melt through stainless steel. Aramaru burns around 1600°F. White binchotan burns at 2,200 degrees Fahrenheit.

If you want to do it at home, you can make your own irori at home using a large flower pot. Pack it with ash and coarse sand. Do not use playground sand because it is too fine and the skewers won’t stay in position unless you drive them deep. If you are worried about your food sliding down the skew into the sand, place a lemon at the bottom.