store-bought sushi rice seasoning, to taste
4½ cups (24 ounces) cooked medium-grain sushi rice
2 cups (10 ounces) chopped imitation crab, divided
1/2 cup mayonnaise
5 tablespoons spicy mayonnaise, divided
3/4 cup (5 ounces) minced sashimi-grade tuna
1/2 tablespoon sesame oil
1/2 cup (3 ounces) ahi sashimi, for rosette furikake
1/2 avocado, thinly sliced
8 thin slices cucumber
shiso leaves, cut into thin ribbons
bubu arare (seasoned rice pearls; optional)
unagi sauce (optional)
For the cake:
Add about 5 tablespoons store-bought sushi rice seasoning to cooked rice and mix evenly. Let rice cool to room temperature.
Put crab in a towel to squeeze out excess moisture. In a bowl, add the crab and mayonnaise and mix well. Cover and set aside in the fridge.
Make spicy crab salad by using the remaining 1 cup of the imitation crab salad and 2½ tablespoons store-bought spicy mayo. Mix well. Cover and set aside in the fridge.
Make the spicy ahi by combining the minced sashimi-grade tuna, 2½ tablespoons spicy mayo and sesame oil. Mix well. Cover and set aside in the fridge.
For the sashimi rosette:
Cut about 9 thin slices of sashimi.
Form 1 slice into a tight cylinder and let it stand up. This is the center of the rosette. Wrap that cylinder with remaining slices to form rose petals. Set aside in the fridge.
To assemble the cake:
Line a 6- by 2-inch cake pan with plastic wrap.
Add 1 cup (5½ ounces) crab salad mix to the pan, making an even layer.
Make a second layer with 1 cup of sushi rice. Top with furikake. Then line the side of the pan up to the edge with 1¾ cups of sushi rice to create an outer shell. Use a small glass jar with plastic wrap to help even and smooth the layer.
Add spicy crab mix, making an even layer. Add slices of avocado to form another layer. Add another 1/2 cup of rice and sprinkle with furikake. Add another layer of spicy ahi.
Add 1¼ cup (6 ounces) of sushi rice, cover with plastic wrap, then, using a cutting board, press down to mold the cake into shape.
Invert cake onto a plate or cake board. Cover sides with sesame seeds.
Garnish with thinly sliced cucumbers, ahi rosette, shiso leaves, edible flowers and sesame seeds. Serve the cake with bubu arare and unagi sauce, if using.