Peel the onions and slice 1/4 inch off the top (save as a lid); use a small paring knife to trim the centers out of the onions (leave 3 or 4 layers intact).
Mince half of the onion centers that were removed and mix into the meat (the remainder of the removed onion can be saved for another recipe).
If using rice, boil it in salted water for about 10 minutes.
Begin browning the meat in butter; add rice if using.
Also add cinnamon, turmeric, salt, pepper, chopped herbs (if using) to the meat mixture and cook for an additional 5 minutes; remove from heat and let cool.
Stuff onions with filling and pack tightly into a pan so that they keep their shape and don't spill their filling; replace onion tops.
Add broth until it comes less than halfway up the sides of the onions (or use water flavored with the saffron); cover pan and simmer until the onions are soft, about 20 minutes.
Add a sprinkling of cinnamon to the yogurt.
Serve the dolmas with the yogurt and any pan juices.