Remove the stems of the mushrooms and stuff half of them with ground meat, making a slight indentation in the center.
Lightly oil the takoyaki pan and place the stuffed mushrooms, flipping them over and cooking both sides. Sprinkle white sesame on the surface of the mushrooms without ground meat.
Apply teriyaki sauce on the ground meat, then layer the lettuce, cherry tomatoes, pickles, and sliced cheese.
Place the remaining mushrooms on top and insert a toothpick.
