As soon as Mark started to eat

[Bassim]

Have I made any mistakes?

As soon as Mark started to eat, he noticed that something was wrong. When a waiter came over, Mark said, "I ordered a veal steak, but this on the plate is an old ox." The waiter blushed, apologised and went with the plate back to the kitchen. He returned about twenty minutes later with the right order and told Mark that was on the restaurant.

 

[tedmc]

...but this [STRIKE]on the plate[/STRIKE] is an old ox."

The common phrase is "on the house".

...[STRIKE]went[/STRIKE] [STRIKE]with[/STRIKE] took the plate back to the kitchen

told Mark [STRIKE]that[/STRIKE] the meal/food was on the [STRIKE]restaurant[/STRIKE] house.