What did I eat?

One evening on my recent trip to Japan we went to this restaurant near our hotel in Tokyo that didnft have English menus, only photos. I ordered these square pieces of meat, cooked on the edges and red inside, thinking that it was tuna. When the waiter delivered it, he said something in Japanese which I obviously didnft understand, except for the word gsteakh. It didnft taste anything like tuna (or any other fish, for that matter). I think it may have been horse meat. I took a photo of the receipt, hoping to ask someone later. Itfs one of the first two items, for 590 yen – the other one should be fried chicken.

http://i121.photobucket.com/albums/o211/mafepero/IMG_20170410_16270616...

Thanks

Maguro(Tune) Steak

others;
Chicken Caesar Salad
Karaage Fried Chicken
Gyoza dumplings
Water(0 yen)
Coke

The receipt says tuna steak.

Thanks. I am surprised, as it really didn't taste like tuna to me. I guess it wasn't a prime cut, so to speak.