Butaman of 551(551の豚まん) is the famous food in Osaka that many tourists buy it as a souvenir. You would often see the bag that says 551 when you are using public transportation.
The Butaman of 551 is a type of steamed pork bun or bread dumpling which the filling is made with ground pork and chopped onions. It tastes like sweet and salty so it might be little greasy and heavy in certain people but for me, hands down it’s one of my favorites.
Last but not least, you don’t wanna miss the steamed pork dumpling called Shumai(焼売) which is a kind of Chinese dumpling. The filling is almost the same as Butamn but Shumai skin is different from Butaman, which is made from flour. So getting Shumais is the icing on the cake when you buy Butamans. Anyway, both are really addictive food.