招 (zhāo): This character means “to beckon,” “to attract,” or “to wave towards.” Think of a hand gesture (手) used to call someone over.
牌 (pái): This character means “signboard,” “placard,” or “brand.” It originally referred to a wooden tablet or plate.
菜 (cài): This is the common character for “dish,” “cuisine,” or “vegetable.”
When you combine them, `招牌 (zhāopái)` becomes “signboard,” the main sign a business uses to attract customers. Adding `菜 (cài)` turns it into the “signboard dish”—the star of the show that represents the entire restaurant's quality and brand.