Finely slice the green onion. Clean and slice the squid. Cut the tentacles into bite sized pieces.
Heat a pan over high heat. Add butter and stir fry the squid quickly. Be careful not to cook for too long!
Swirl in the ponzu sauce, mix quickly and transfer to a serving plate while still warm. Top with green onions, squeeze mayonnaise on top and it's done.
Story Behind this Recipe
A friend of my mother's taught me this recipe. Apparently it's a standard item at izakaya.
Avoid overcooking the squid! If you do, it'll become hard and dry. Turn off the heat when you think it's cooked through! You can add ponzu sauce after turning off the heat. If there's a lot of liquid in the pan, remove the squid, simmer down the liquid, and pour over the squid.