In a medium bowl, combine beef, egg, rice, salt, and onion.
Mixture will be soft. Form meat into 12 thin patties, each about 3 in. wide. Put a wedge of hard-boiled egg in center of each patty, then press meat around eggs, forming 12 balls. Cover and refrigerate while you prepare sauce.
In a blender or food processor, combine chicken broth, tomato sauce, chipotles, and garlic; blend until smooth.
Pour sauce through strainer into a medium saucepan and add meatballs and bay leaf. Bring to a boil, then reduce heat to a simmer. Cover pot and cook meatballs in sauce, turning occasionally, until they're cooked through, about 25 minutes.