Bash the chicken tenders flat with the back of a knife. If there are any sinews, cut or remove them gently with your knife.
Sprinkle the flattened chicken with cooking sake.
Take the mentaiko out of their sacs and spread on the chicken.
Wrap up with plastic wrap. Place the rolled chicken on a plate, and microwave for 3 and a half minutes.
Cut into easy-to-eat pieces with a knife, and they're done! I recommend dipping them in ponzu sauce.
Story Behind this Recipe
You see this served a lot at izakaya (Japanese pubs)!! I first encountered them when I went to Kyoto on a trip. This is so good. I adapted this so that it can be made easily in a microwave. You can get rid of any gaminess and soften the chicken by using sake.
Don't bash the chicken with the blade side of your knife! Wrap the chicken quite tightly in plastic wrap!! Please adjust the cooking time depending on your microwave. If the chicken tenders turn white they're done! You can freeze them as-is, so they're very handy for bentos.