"Excuse me, do you have soup or chicken?"
Translation:Извините, у вас есть суп или курица?
Informal ты not accepted. i could see this being said to a friend who's serving something you cant eat
In sentences like this, the thing that is possessed is the subject and the person that possesses them is the object. So, you would use the accusative form тебя.
I tried Извините, у тебя есть суп или курица and it didn't like my use of тебя.
Because курица is the grammatical subject – the sentences means word by word: "Excuse (me), is soup or chicken by you?"
I'd say that извини is informal and извините is formal, therefore извините вы и извини ты