Make the ponzu sauce. Add the lemon juice, mirin, and soy sauce to a small mixing bowl. Give it a little stir and then it’s ready to go.
Cut the avocados in half and remove the pit.
Brush olive oil on the flesh of the avocado using a basting brush. This will prevent the avocados from sticking to the grill.
Place the avocados flesh side down on the grill. Grill for about 5 minutes at around 350°, or until nice grill marks develop.
Pour a little of the ponzu sauce inside the avocado where the pit was. Serve immediately while still warm. I like to serve these with a spoon and you can just scoop the avocado right out of the peel.