1. Cook the Salmon: Coat the salmon generously with unagi sauce (or teriyaki marinade) on both sides. Place fish on foil-lined sheetpan and broil on low heat for 35-40 minutes.
2. Season the Rice: Once the rice has finished cooking, transfer to a bowl and mix in sushi seasoning. Set aside.
3. Make Tempura Batter: In a medium bowl, whisk together egg and ice water. In a separate bowl, stir both flours together with a fork, getting rid of any lumps. Whisk flour mixture into egg/water mixture until smooth. Season with salt & cayenne pepper. Set aside.