Cut the 1/4 apple in half. Slice the halves into thin slices and soak in salted water. Thinly slice the celery. You can use the celery leaves if you prefer.
Heat a frying pan and add the oil. Add the pork and a pinch of salt. Cook on medium heat. Once the meat changes color, pour in the sake.
Add the celery and drained apples in order. Lightly cook. Season with salt and pepper and turn off the heat. Swirl in the ponzu to finish.
I use a mild type of ponzu. You can adjust it however you want.
Story Behind this Recipe
This recipe is a variation of "Easy Ponzu Sauté with Pork and Celery"
I used thinly sliced pork belly. I recommend this as they cook easily and will come out tender. To get the most out of the ponzu, it's best to add it after stopping the heat, but it's up to you. If making this for a bento, serve the ponzu in a separate container. Adding it right before you eat will also prevent leaking in your lunchbox.