First, you'll need to preheat your oven to broil at 550 degrees F or 290 degrees C for around 3 minutes. As your oven preheats, cut your unagi in half or thirds. This should depend on the size of your serving bowls.
Cook the rice in a cooking pot or rice steamer for about 8 minutes.
Line your baking sheet with aluminum foil and then brush a light layer of oil on it. Place the unagi on the baking sheet.
Place the baking sheet on the middle rack of the oven and then broil on high heat for around 5 to 7 minutes. You don’t need to flip it.
After the 7 minutes, take out the unagi, and then brush it all over with the sauce.
Continue to broil for an additional 30 to 60 seconds, or until you see some bubbles on top of your unagi.
Serve your cooked rice in a bowl and then brush or pour unagi sauce on top of the rice. Then, serve unagi on top of the rice and brush or pour more unagi sauce. You can also sprinkle some sansho, but this is optional.