Cut the green onion into small slices and thinly slice the garlic.

Remove the contents of the mentaiko by making a slit.

Slice the chicken breast diagonally into 1cm pieces, mix with salt koji in a bag, and let it rest for 10 minutes.

Mix the cooked rice and egg in a bowl until evenly combined.

Heat salad oil in a pan over low heat, fry garlic until lightly browned, then remove. Add chicken and cook until browned, flip, cover, and steam for 3 minutes until cooked through. Remove from the pan.

Wipe the pan clean, add butter, and heat over medium. Add the rice mixture and stir-fry until fluffy. Pour soy sauce around the edges and mix well. Add mentaiko and green onion, stir quickly.