Assembly
Step 1
For the Tuna: In a rimmed dish or container that can fit both tuna steaks side by side in a single layer, combine soy sauce, toasted sesame oil, and brown sugar, until sugar dissolves. Place tuna in the container and coat with marinade. Let sit in fridge for 10 minutes.
In a shallow dish, combine white and black sesame seeds, spreading into an even layer. Once tuna has finished marinading, coat each steak with sesame seeds. Set aside in fridge until ready to cook.
Step 2
For the Slaw: Combine slaw ingredients, aside from the Spicy Gochu Lil Croutons, in a large bowl. In a small bowl, combine soy miso dressing ingredients until smooth.
Step 3
To Assemble: Heat a medium cast-iron skillet over medium-high heat. Once pan is hot, reduce heat to medium, add olive oil, then carefully place tuna steaks into the pan. Sear until crust forms, then flip. Repeat on all sides, being sure to keep the centre raw. Remove from pan and set aside.
Toss slaw with dressing. Slice tuna steaks and place on top of slaw. Shake Spicy Gochu Lil Croutons on top of the slaw and serve immediately.