Cut the roots off the pea shoots and chop them into 1cm pieces. Mix with salt in a bowl and let sit for 5 minutes until softened. Squeeze out excess water.

Cut the hanpen diagonally in half, then slice each piece horizontally to create a pocket.

In a separate bowl, mix the tuna, pea shoots, mayonnaise, and white sesame seeds to create the filling.

Stuff each hanpen pocket with 1/4 of the filling. Repeat for all pieces to make 4 stuffed hanpen.

Heat salad oil in a frying pan over medium heat. Place the stuffed hanpen in the pan and cook, flipping occasionally, until golden brown on both sides.