Remove the stem, seeds and membrane from each pepper. Wash inside and out. Cook peppers in boiling salted water 5 minutes; drain.
Cook and stir ground beef (or turkey) and onion in large skillet until onion is tender. Drain off fat. Stir in salt, garlic salt, rice and 1 cup of the tomato sauce; heat through.
Lightly stuff each pepper with approximately 1/2 cup meat mixture. Stand peppers upright in ungreased baking dish. Pour remaining tomato sauce over peppers.
Cover and bake 45 minutes. Uncover and bake 15 minutes longer.