Pan Mexicano is a business chain selling Mexican products, with stores located in Los Flores and East Los Santos. The Pan Mexicano Bakery is also a separate business, owned by Pan Mexicano. It is inaccessible to the player and plays no part in the storyline whatsoever.
In Spanish, 'Pan Mexicano' means 'Mexican Bread'. Hecho Aqui Mismo, the Spanish writing underneath Pan Mexicano, means 'Done Right Here', which, combined, means 'Mexican Bread Done Right Here'.