Combine reserved pineapple juice, chicken, and garlic in a small baking dish. Cover, and refrigerate for 1 hour.
Preheat oven to 400 degrees F (200 degrees C).
Remove chicken from pineapple. Saute chicken and garlic in a very hot pan, so that the chicken browns just slightly.
Roll out pizza dough on a 16 inch pizza pan. Bake dough for approximately 7 minutes, and then remove from oven. Brush dough with a thin layer of teriyaki sauce, then a layer of the onion, and top with Cheddar cheese. Then top with chicken, reserved pineapple chunks, and feta cheese. Bake for an additional 15 minutes, or until cheese is bubbly and slightly browned.