Pat the cleaned squid very dry with paper towels. Cut the squid bodies into 1/2-inch rings and leave small tentacles whole; halve larger tentacles if desired.
Heat the oil in a wide skillet or sauté pan over medium heat. Add the garlic and cook for 20 to 30 seconds, just until fragrant; do not let it brown deeply.
Add the squid, soy sauce, vinegar, water, bay leaves, black pepper, and optional brown sugar. Bring the liquid to a gentle simmer. Once it simmers, cook for 2 minutes, stirring once or twice.
Use tongs or a slotted spoon to transfer the squid to a clean bowl. Leave the sauce in the skillet.
Increase the heat to medium-high and simmer the sauce for 5 to 7 minutes, or until it reduces slightly and tastes balanced. Remove and discard the bay leaves.
Return the squid and any juices in the bowl to the skillet. Toss for 30 to 60 seconds, only until the squid is heated through and coated. Serve right away over hot rice, topped with green onions if desired.