Combine soy sauce, garlic, vinegar, onions, pepper, and bay leaves in a large bowl.
Add chicken, making sure it is well submerged in that sauce.
Cover and refrigerate, letting it marinate for at least three hours, though an overnight stay is preferred.
Transfer to pot, cover and cook on medium heat until it boils, then turn down to simmer, cooking until done.
Add more water for more broth (sabaw), if necessary. I usually start with a ½ cup of water.
Make sure to taste (obviously when chicken is done), only add a little bit of garlic salt if needed (for example, if you add too much water/sabaw and find the taste escaping).
Once cooked transfer to sheet pan and hit under broiler for a few minutes, just to get a little bit of that sexy brown crisp. Then transfer back to pot or serving dish and drizzle the sabaw and onions all over.
Serve with rice and enjoy.